#1MAINST Main Street Capital Corporation CAPITAL CORPORATION Analysts' and Investors' Day June 2023 NYSE: MAIN mainstcapital.com#2Disclaimers Main Street Capital Corporation (MAIN) cautions that statements in this presentation that are forward-looking, and provide other than historical information, involve risks and uncertainties that may impact our future results of operations. The forward-looking statements in this presentation are based on current conditions as of June 22, 2023, and include, but are not limited to, statements regarding our goals, beliefs, strategies, future operating results and cash flows, operating expenses, investment originations and performance, available capital, payment and the tax attributes of future dividends and shareholder returns. Although our management believes that the expectations reflected in any forward- looking statements are reasonable, we can give no assurance that those expectations will prove to have been correct. Those statements are made based on various underlying assumptions and are subject to numerous uncertainties and risks, including, without limitation: our continued effectiveness in raising, investing and managing capital; adverse changes in the economy generally or in the industries in which our portfolio companies operate; the impacts of macroeconomic factors on MAIN and its portfolio companies' business and operations, liquidity and access to capital, and on the U.S. and global economies, including impacts related to the COVID-19 pandemic and other public health crises, risk of recession, inflation, supply chain constraints or disruptions and rising interest rates; changes in laws and regulations or business, political and/or regulatory conditions that may adversely impact our operations or the operations of our portfolio companies; the operating and financial performance of our portfolio companies and their access to capital; retention of key investment personnel; competitive factors; and such other factors described under the captions "Cautionary Statement Concerning Forward-Looking Statements," "Management's Discussion and Analysis of Financial Condition and Results of Operations" and "Risk Factors" included in our filings with the Securities and Exchange Commission (www.sec.gov), including our most recent annual report on Form 10-K and subsequently filed quarterly reports on Form 10-Q. We undertake no obligation to update the information contained herein to reflect subsequently occurring events or circumstances, except as required by applicable securities laws and regulations. Main Street Capital Corporation MAINST CAPITAL CORPORATION MAIN has filed a registration statement (which includes a prospectus) with the SEC for any offering to which this communication may relate and may file one or more supplements to the prospectus in the future. Before you invest in any of MAIN's securities, you should read the registration statement, the prospectus and the applicable prospectus supplement(s) in order to fully understand all of the implications and risks of an offering of MAIN's securities. You should also read other documents MAIN has filed with the SEC for more complete information about MAIN and its securities offerings. You may access these documents for free by visiting EDGAR on the SEC website at www.sec.gov. Alternatively, MAIN will arrange to send you any applicable prospectus and prospectus supplement if you request such materials by calling us at (713) 350-6000. These materials are also made available, free of charge, on our website at www.mainstcapital.com. Information contained on our website is not incorporated by reference into this communication. NYSE: MAIN The summary descriptions and other information included herein are intended only for informational purposes and convenient reference. The information contained herein is not intended to provide, and should not be relied upon for, accounting, legal or tax advice or investment recommendations. Before making an investment decision with respect to MAIN, investors are advised consult with their tax, financial, investment and legal advisors. mainstcapital.com#3A Differentiated Approach Focus on Lower Middle Market debt and equity investment strategy and internally managed operating structure differentiates MAIN from other investment firms Attractive and growing Asset Management Business, primarily driven by strong direct lending capabilities, provides further differentiation ● Primarily Invests in the under-served Lower Middle Market (LMM) Targets companies with revenue between $10 million - $150 million; EBITDA between $3 million - $20 million ● Equity investments are key component of LMM portfolio Key contributor to our 112% growth (5.0% CAGR) in net asset value (NAV) per share since 2007 through March 31, 2023 Generate dividend income and realized gains to support dividend growth ● Internally-managed operating structure Alignment of interests between MAIN management and shareholders Provides cost efficient model with significant operating leverage Attractive asset management advisory business Significant management ownership / investment in MAIN Strong capitalization and liquidity position - stable, long-term debt and significant available liquidity to take advantage of future opportunities ● ● MAINST ● CAPITAL CORPORATION (1) Includes cash and undrawn portion of debt capital as of May 31, 2023 Main Street Capital Corporation Favorable opportunities in capital markets through investment grade rating of BBB-/Stable from Standard & Poor's Global Ratings and BBB-/Stable from Fitch Ratings Total liquidity in excess of $670 million at May 31, 2023(¹) NYSE: MAIN mainstcapital.com#4LMM Investment Strategy LMM investment strategy differentiates MAIN from its competitors and provides attractive risk-adjusted returns Main Street Capital Corporation ● Investment Objectives High cash yield from secured debt investments (12.4% weighted- average cash coupon as of March 31, 2023); plus Dividend income, fair value appreciation and periodic capital gains from equity investments ● Investments are structured for (i) protection of capital, (ii) high recurring income and (iii) meaningful capital gain opportunity ● Focus on self-sponsored, "one stop" financing opportunities Partner with business owners, management teams and entrepreneurs Provide highly customized financing solutions Recapitalization, buyout, growth and acquisition capital ● ● MAINST ● CAPITAL CORPORATION ● Extensive network of grass roots referral sources Strong and growing "Main Street" brand recognition / reputation Investments have low correlation to the broader debt and equity markets and attractive risk-adjusted returns NYSE: MAIN Unique LMM strategy, combined with MAIN's perpetual capital structure and goal to be long-term partners, results in a highly diversified and high-quality investment portfolio mainstcapital.com#5LMM Investment Opportunity MAIN targets LMM investments in established, profitable companies Characteristics of LMM provide beneficial risk- reward investment opportunities Large and critical portion of U.S. economy 195,000+ domestic LMM businesses (1) ● MAINST LMM is under-served from a capital perspective and less competitive ● CAPITAL CORPORATION Inefficient asset class generates pricing inefficiencies • Typical entry enterprise values between 4.5X-6.5X EBITDA ● Typical entry leverage multiples between 2.0X-4.0X EBITDA to MAIN debt investment Partner relationship with the management teams of our portfolio companies vs. a "commoditized vendor of capital" NYSE: MAIN (1) Source: U.S. Census 2017 - U.S. Data Table by Enterprise Receipt Size; 2017 County Business Patterns and 2017 Economic Census; includes Number of Firms with Enterprise Receipt Size between $10,000,000 and $99,999,999 Main Street Capital Corporation mainstcapital.com#6LMM Investment Portfolio(1) LMM investment portfolio consists of a diversified mix of secured debt and lower cost basis equity investments 79 portfolio companies / $2.1 billion in fair value 51% of total investment portfolio at fair value ● ● Debt yielding 12.6% (2) (73% of LMM portfolio at cost) 99% of debt investments have first lien position 63% of debt investments earn fixed-rate interest ● ● ● Equity ownership in all LMM portfolio companies representing 41% average ownership position (27% of LMM portfolio at cost) Lower entry multiple valuations, lower cost basis Opportunity for dividend income, fair value appreciation and ● ● MAINST ● CAPITAL CORPORATION Approximately 830 basis point net cash interest margin vs "matched" fixed interest rate on SBIC debentures periodic capital gains 64% of LMM companies (3) with direct equity investment are currently paying dividends Fair value appreciation of equity investments supports Net Asset Value per share growth $384.7 million, or $4.82 per share, of cumulative pre-tax net unrealized appreciation at March 31, 2023 (1) As of March 31, 2023 (2) Weighted-average effective yield is calculated using the applicable interest rate as of March 31, 2023 and includes amortization of deferred debt origination fees and accretion of original issue discount, but excludes fees payable upon repayment of the debt instruments and any debt investments on non-accrual status NYSE: MAIN (3) Includes the LMM companies that (a) MAIN has a direct equity investment and (b) are flow-through entities for tax purposes; based upon dividend income for the trailing twelve month period ended March 31, 2023 Main Street Capital Corporation mainstcapital.com#7LMM Investment Portfolio(1) LMM investment portfolio is a pool of high quality, seasoned assets with attractive risk-adjusted return characteristics ● Median LMM portfolio credit statistics (²): Senior leverage of 2.9x EBITDA through MAIN debt position 2.6x EBITDA to senior interest coverage Total leverage of 3.1x EBITDA including debt junior in priority to MAIN Free cash flow de-leveraging improves credit metrics and increases equity appreciation ●. MAINST Average investment size of $26.7 million at fair value or $21.9 million on a cost basis (less than 1% of total investment portfolio) CAPITAL CORPORATION Opportunistic, selective posture toward new investment activity over the economic cycle ● High quality, seasoned LMM portfolio Total LMM investment portfolio at fair value equals 122% of cost ● Equity component of LMM portfolio at fair value equals 191% of cost Significant portion of LMM portfolio has de-leveraged and a majority of the LMM portfolio investments have experienced equity appreciation - 50 LMM portfolio companies with unrealized appreciation on equity investments (1) As of March 31, 2023 (2) These credit statistics exclude portfolio companies on non-accrual and four companies for which EBITDA is not a meaningful metric Main Street Capital Corporation NYSE: MAIN - Net unrealized appreciation on LMM equity investments of $427.2 million mainstcapital.com#8LMM Portfolio by Industry (as a Percentage of Cost)(¹) ■ Machinery, 11% Construction & Engineering, 7% ■ Containers & Packaging, 5% ■ Diversified Consumer Services, 4% ■ Distributors, 4% ■Auto Components, 4% ■ Electronic Equipment, Instruments & Components, 3% ■ Textiles, Apparel & Luxury Goods, 3% ■Specialty Retail, 3% Health Care Providers & Services, 2% ■ Media, 2% Hotels, Restaurants & Leisure, 2% Household Products, 1% ■ Other, 3% (1) As of March 31, 2023 Main Street Capital Corporation Professional Services, 7% ■Tobacco, 7% ■ Computers & Peripherals, 5% ■IT Services, 4% ■Leisure Equipment & Products, 4% ■ Software, 4% ■ Energy Equipment & Services, 3% ■Internet Software & Services, 3% Food Products, 3% ■ Internet & Catalog Retail, 2% ■Health Care Equipment & Supplies, 2% ■Household Durables, 1% Building Products, 1% NYSE: MAIN MAINST CAPITAL CORPORATION mainstcapital.com#9Diversified LMM Portfolio (as a Percentage of Cost)(¹) Invested Capital by Transaction Type LBO/MBO Acquisition 27% 6% 3% Recapitalization/ Refinancing (1) As of March 31, 2023 (2) Based upon portfolio company headquarters Main Street Capital Corporation 64% Growth Capital Invested Capital by Geography (2) NYSE: MAIN 28% 22% 26% MAIN ST CAPITAL CORPORATION 14% 10% mainstcapital.com#10LMM Investments Represent a Mature and Diversified Portfolio MAIN'S LMM portfolio includes: 19 portfolio companies which MAIN has been invested in for over a decade (24% of total companies) 46 portfolio companies which MAIN has been invested in for over 5 years (58% of total companies and 43% of the total LMM portfolio at fair value) MAIN has completed follow on investments to fund either a growth activity or an equity owner value creation event in over one- third of these portfolio companies ($) in millions ($) in millions $350.0 $300.0 $250.0 $200.0 $150.0 $100.0 $50.0 $0.0 $1,000.0 $900.0 $800.0 $700.0 $600.0 $500.0 $400.0 $300.0 $200.0 $100.0 $0.0 8 > 5-6 yrs 19 Investments by Investment Date(¹) > 10 yrs 10 > 6-8 yrs > 8-10 yrs FV % Cumulative Investments by Investment Date(¹) 28 > 8 yrs 9 FV $ 39 MAINST > 6 yrs CAPITAL CORPORATION 19 > 10 yrs 46 > 5 yrs 16.0% 14.0% 12.0% 10.0% 8.0% 6.0% 4.0% 2.0% 0.0% 50.0% 45.0% 40.0% 35.0% 30.0% 25.0% 20.0% 15.0% 10.0% 5.0% 0.0% FV $ FV % (1) Aging as of June 19, 2023; fair value as of March 31, 2023; based upon original investment date in each portfolio company and including the value of all investments in each portfolio company in any period Main Street Capital Corporation NYSE: MAIN mainstcapital.com % of Total LMM Investments at FV % of Total LMM Investments at FV#11Private Loan Investment Strategy Private Loan portfolio investments are primarily debt investments in privately held companies which have primarily been originated directly by MAIN or to a lesser extent through strategic relationships with other credit funds on a collaborative basis (often referred to in the debt markets as "club deals" because of the small lender group size) MAIN's Private Loan investments are typically made to a company owned by or being acquired by a private equity sponsor ● Investment Objectives Access proprietary investments with attractive risk-adjusted return characteristics Generate cash yield to support MAIN monthly dividend ● ● Investment Characteristics Investments in companies that are consistent with the size of companies in our LMM and Middle Market portfolios ● Investments in secured debt investments First lien, senior secured debt investments Floating rate debt investments ● ● 8% -12% targeted gross yields ● ● MAINST ● CAPITAL CORPORATION Proprietary investments originated directly by MAIN or through strategic relationships with other investment funds on a collaborative basis Current Private Loan portfolio companies have weighted-average EBITDA of approximately $38.1 million(1) Weighted-average effective yield of 12.4% (2) Net returns positively impacted by lower overhead requirements and modest use of leverage Floating rate debt investments provide matching with MAIN's floating rate Credit Facilities (3) (1) As of March 31, 2023; this calculation excludes two Private Loan portfolio companies as EBITDA is not a meaningful metric for these portfolio companies (2) Weighted-average effective yield is calculated using the applicable interest rate as of March 31, 2023 and includes amortization of deferred debt origination fees and accretion of original issue discount, but excludes fees payable upon repayment of the debt instruments and any debt investments on non-accrual status NYSE: MAIN (3) See Main Street Investor Presentation, available on the MAIN website, for the definition of MAIN's Credit Facilities (page 11) and for additional details about MAIN's Credit Facilities (page 42) Main Street Capital Corporation mainstcapital.com#12Private Loan Investment Portfolio(¹) Private Loan investment portfolio provides a diversified mix of investments and sources of income to complement the LMM investment portfolio 86 investments / $1.5 billion in fair value 36% of total investment portfolio at fair value ● Average investment size of $17.8 million, at cost (less than 1% of total portfolio) ● Investments in secured debt instruments 97% of Private Loan portfolio is secured debt 99% of Private Loan debt portfolio is first lien term debt ● MAINST CAPITAL CORPORATION ● Debt yielding 12.4% (²) 98% (1) of Private Loan debt investments bear interest at floating rates(3), providing matching with MAIN's floating rate Credit Facilities (4) Approximately 525 basis point effective interest margin vs "matched" floating rate on MAIN's Credit Facilities (4) NYSE: MAIN (1) As of March 31, 2023 (2) Weighted-average effective yield is calculated using the applicable interest rate as of March 31, 2023 and includes amortization of deferred debt origination fees and accretion of original issue discount, but excludes fees payable upon repayment of the debt instruments and any debt investments on non-accrual status (3) 95% of floating interest rates on Private Loan debt investments are subject to contractual minimum "floor" rates (4) See Main Street Investor Presentation, available on the MAIN website, for the definition of MAIN's Credit Facilities (page 11) and for additional details about MAIN's Credit Facilities (page 42) Main Street Capital Corporation mainstcapital.com#13Portfolio Investments - Vintage Analysis ($ Invested)(1)(3) ($) in millions ($) in millions $1,125.0 $1,000.0 $875.0 $750.0 $625.0 $500.0 $375.0 $250.0 $125.0 $- $1,125.0 $1,000.0 $875.0 $750.0 $625.0 $500.0 $375.0 $250.0 $125.0 $- 41 2017 and prior 11 2017 and prior Lower Middle Market 10 2018 6 2018 2019 6 2019 12 10 2020 Cost Fair Value Middle Market 1 2020 Cost Fair Value 2021 8 2021 5 2022 1 2022 2023 0 2023 ($) in millions ($) in millions $1,125.0 $1,000.0 $875.0 $750.0 $625.0 $500.0 $375.0 $250.0 $125.0 $- $1,125.0 $1,000.0 $875.0 $750.0 $625.0 $500.0 $375.0 $250.0 $125.0 $- 19 2017 and prior NYSE: MAIN 84 7 2018 23 Private Loan 2017 and 2018 prior 6 2019 I Cost Fair Value Total(2) 14 6 2020 2019 14 2020 Cost Fair Value MAINST CAPITAL CORPORATION 28 HI 2021 50 2021 (2) Including Other Portfolio investments and excluding MAIN's external investment manager, MSC Adviser I, LLC (3) Numbers at the top of bars for each year in charts represent the number of portfolio investments based on the date of MAIN's initial investment in each portfolio company Main Street Capital Corporation 19 2022 27 (1) Aging as of June 19, 2023; fair value as of March 31, 2023; based upon original investment date in each portfolio company and including the value of all investments in each portfolio company in any period 2022 2023 2 2023 mainstcapital.com#14% of total % of total Portfolio Investments - Vintage Analysis (% Invested)(1) 40% 35% 30% 25% 20% 15% 10% 5% 0% 40% 35% 30% 25% 20% 15% 10% 5% 0% 2017 and prior 2017 and prior 2018 2018 Lower Middle Market 2019 2020 Cost Fair Value Middle Market 2019 2020 Cost Fair Value 2021 2021 2022 2022 2023 2023 % of total 40% 35% 30% 25% 20% 15% 10% 5% 0% 40% 35% 30% 25% 20% 15% 10% 5% 0% 2017 and prior 2017 and prior 2018 2018 Private Loan 2019 2020 Cost Fair Value Total(2) 2019 2020 MAINST J Cost Fair Value CAPITAL CORPORATION 2021 2021 2022 2022 (1) Aging as of June 19, 2023; fair value as of March 31, 2023; based upon original investment date in each portfolio company and including the value of all investments in each portfolio company in any period (2) Including Other Portfolio investments and excluding MAIN's external investment manager, MSC Adviser I, LLC Main Street Capital Corporation NYSE: MAIN 2023 2023 mainstcapital.com#15Asset Management Business MAIN's asset management business represents additional income diversification and the opportunity for greater shareholder returns MAIN's internally managed operating structure provides MAIN's shareholders the benefits of this Asset Management Business Growth of asset management business is increasingly driven by MAIN's Private Loan investment strategy MAIN(1) is the investment adviser to several third party clients in its Asset Management Business ● MAIN(1) is the investment adviser to and administrator of MSC Income Fund, Inc. (MSIF), a non-listed BDC MAIN(1) provides asset management services, including sourcing, diligence and post-investment monitoring ● ● ● MAIN(1) is the investment adviser and administrator to a private fund and a separately managed account with the investment strategies for these clients solely focused on MAIN's Private Loan investment strategy MAIN recently launched fund raising for its second private fund ● MAINST ● CAPITAL CORPORATION - Benefits to MAIN Highly predictable source of recurring base management fee income, with opportunity for upside through incentive fees No significant increases to MAIN's operating costs to provide services (utilize existing infrastructure and investment capabilities and leverage fixed costs) Monetizing the value of MAIN franchise Significant positive impact on MAIN's financial results $8.1 million contribution to net investment income in the first quarter of 2023(2) ● MAIN(1) receives management fees and incentive fees Base management fee of 1.75% of total assets Incentive fees - 20% of net investment income above a hurdle rate and 20% of net realized capital gains - $22.2 million contribution to net investment income in the year ended December 31, 2022(²) - - $103.2 million of cumulative unrealized appreciation as of March 31, 2023 NYSE: MAIN (1) Through MSC Adviser I, LLC (the External Investment Manager), MAIN's wholly-owned unconsolidated subsidiary (2) Contribution to Net Investment Income includes (a) dividend income received by MAIN from the External Investment Manager and (b) operating expenses allocated from MAIN to the External Investment Manager Main Street Capital Corporation mainstcapital.com#16Alignment of Interests Between MAIN Management and MAIN Investors Management Alignment Has asset growth been accretive to shareholders - earnings, dividends, NAV per share? MAIN Growth %(1) ● 1-YR 3-YR 5-YR From End of IPO Year ● Total Assets 14% 73% 79% 2,353% Total Assets Per Share 3% 40% 32% 175% DNII Per Share(2) 27% 45% 43% 395% Monthly Dividends Per Share (3) 5% 7% 17% 99% Total Dividends Per Share (4) NYSE: MAIN 15% 25% 10% 123% MAINST CAPITAL CORPORATION Benefits of internally managed structure Greater incentives to maximize increases to shareholder value and rationalize equity and debt capital raises •100% of MAIN's management efforts and activities are for the benefit of the BDC Favorable comparison of the above vs our peers, the majority of which have increased assets under management, but not key shareholder value metrics Management Ownership MAIN's senior executives and Board of Directors own 3.3 million shares worth $130.0 million (5) NAV Per Share $34.0 million purchased as part of or since 2007 IPO, including $4.1 million purchased in 2022 and Q1 2023 Broad / significant ownership throughout greater MAIN team through restricted stock Focuses our personnel on key drivers of value to MAIN shareholders - DNII, Dividends and NAV per share Restricted stock grants represented approximately 50% of 2022 total compensation for executive management (1) Through March 31, 2023 (2) 5% 31% 15% 112% See Main Street Investor Presentation, available on the MAIN website, for the reconciliation of Distributable Net Investment Income (DNII) to Net Investment Income (page 38) and for Non-GAAP information disclosures and discussion of DNII (page 48) (3) Excludes supplemental dividends (4) Includes supplemental dividends (5) Based upon closing market price of $39.46/share on March 31, 2023 Main Street Capital Corporation mainstcapital.com#17Efficient and Leverageable Operating Structure MAIN's internally managed operating structure provides significant operating leverage and greater returns for our shareholders "Internally managed" structure means no external management fees or expenses are paid ● Alignment of interest between management and investors Greater incentives to maximize increases to shareholder value and rationalize debt and equity capital raises 100% of MAIN's management efforts and activities are for the benefit of MAIN investors ● MAIN targets total operating expenses(¹) as a percentage of average assets (Operating Expense to Assets Ratio) at or less than 2% ● MAINST CAPITAL CORPORATION ● ● Significant portion of total operating expenses (1) are non-cash Non-cash compensation expenses (3) were 24.9% (2) of total operating expenses (1) Long-term actual results have significantly outperformed target An industry leading position in cost efficiency, with an Operating Expense to Assets Ratio of 1.4%(²) Operating Expense to Assets Ratio of 1.1% (²) excluding non-cash compensation expenses(³) NYSE: MAIN (1) Total expenses excluding interest expense (2) Based upon the trailing twelve month period ended March 31, 2023 (3) See Main Street Investor Presentation, available on the MAIN website, for calculation of non-cash compensation expenses (page 38) and Non-GAAP information disclosures and discussion of DNII (page 48) Main Street Capital Corporation mainstcapital.com#18MAIN Maintains a Significant Operating Cost Advantage Operating Expenses (1) as a Percentage of Total Assets 3.0% 2.5% 2.0% 1.5% 1.0% 0.5% 0.0% MAIN (2) MAIN Excl. Non-cash Comp Exp (3)(4) Other BDCs (5)(6) Other BDCS Excl. Non-cash Comp xp (5) (7) MAINST CAPITAL CORPORATION Commercial Banks (8) (1) Total expenses excluding interest expense (2) Based upon the trailing twelve month period ended March 31, 2023 (3) Based upon the trailing twelve month period ended March 31, 2023, excluding non-cash compensation expense (4) (5) Other BDCs includes dividend paying BDCs that have been publicly-traded for at least two years and have total assets greater than $500 million based on individual SEC Filings as of December 31, 2022; specifically includes: ARCC, BBDC, BCSF, BKCC, CCAP, CGBD, CSWC, FDUS, FSK, GAIN, GBDC, GLAD, GSBD, HRZN, HTGC, MFIC, MRCC, NMFC, OCSL, OFS, ORCC, PFLT, PNNT, PSEC, PTMN, SAR, SCM, SLRC, TCPC, TPVG, TSLX and WHF NYSE: MAIN See Main Street Investor Presentation, available on the MAIN website, for calculation of non-cash compensation expenses (page 38) and Non-GAAP information disclosures and discussion of DNII (page 48) (6) Calculation represents the average for the companies included in the group and is based upon the trailing twelve month period ended December 31, 2022 as derived from each company's SEC filings, including non-cash compensation expenses (7) Calculation represents the average for the companies included in the group and is based upon the trailing twelve month period ended December 31, 2022 as derived from each company's SEC filings, excluding non-cash compensation expenses (8) Source: SNL Financial. Calculation represents the average for the trailing twelve month period ended December 31, 2022 and includes commercial banks with a market capitalization between $500 million and $3 billion Main Street Capital Corporation mainstcapital.com#19MAIN Maintains a Significant Operating Cost Advantage MAIN has the lowest BDC manager costs relative to total economic benefit generated (4) MAIN's actual results equal greater than one- third more efficient than the Top Quartile of all other BDCs 45.0% 40.0% 35.0% 30.0% 25.0% 20.0% 15.0% 10.0% 5.0% MAIN BDC Manager Costs Relative to Total Economic Benefit Generated (1)(2)(3)(4) Top 10% Top Quartile Middle Quartile Average MAINST CAPITAL CORPORATION Bottom Quartile (1) Source: Public company filings (2) Calculated as compensation and management fees divided by [Net Increase in Net Assets (i.e., Net Income) plus compensation and management fees] (3) Amounts represent the total for the most recent five trailing twelve month periods through December 31, 2022 for each respective company; for each applicable BDC not > 5 years past IPO, the first full fiscal year-end post-IPO was used as the starting point for this analysis; see Appendix for details by BDC (4) Comparison columns include all BDCs noted in footnote (3) excluding (a) MAIN and (b) a BDC that had a net decrease in net assets and which would significantly affect the Peer Group comparisons; as an example, the Average would be 56.7% including the BDC with a net decrease in net assets; see Appendix for details Main Street Capital Corporation NYSE: MAIN mainstcapital.com#20Historical Monthly Dividends, NAV and DNII(¹) Per Share MAIN's unique focus on equity investments in the LMM provides the opportunity for significant NAV per share growth MAIN's efficient operating structure provides significant operating leverage, greater dividends and greater overall returns for our shareholders DNII and Dividends Per Share $1.10 $1.00 $0.90 $0.80 $0.70 $0.60 $0.50 $0.40 $0.30 $0.20 I I + I I + I I t 1 I T I I I I I 2008 Recessionary Period 2009 2010 I I I I I I 2011 2012 2013 2014 2015 2016 Monthly Dividends 2017 2018 NYSE: MAIN --DNII per share) 2019 I I I Pandemic Outbreak 2020 MAINST CAPITAL CORPORATION COVID →NAV per share 2021 2022 2023 $28.00 (1) See Main Street Investor Presentation, available on the MAIN website, for the reconciliation of DNII to Net Investment Income (page 38) and for Non-GAAP information disclosures and discussion of DNII (page 48) (2) Includes dividends paid or declared as of June 21, 2023 Main Street Capital Corporation $26.00 $24.00 $22.00 $20.00 $18.00 $16.00 $14.00 $12.00 $10.00 In addition to the monthly dividends above, $4.89 per share of supplemental dividends have been paid or declared since 2007 IPO(²) Annual return on equity averaging approximately 13.5% from 2010 through the first quarter of 2023 NAV Per Share mainstcapital.com#21MAIN's strategy has produced consistent dividend growth since our IPO in 2007, including the impacts of the 2008/2009 recession and the COVID- 19 pandemic MAIN's Strategy Consistently Produces Differentiated Returns MAIN has been able to grow the regular monthly dividend to our shareholders, and has never decreased the regular monthly dividend MAIN has also delivered significant additional benefits through supplemental dividends ● Consistent cash dividend yield - dividends paid monthly MAIN has never decreased its monthly dividend rate Paid or declared periodic supplemental dividends from January 2013 through June 2023 ● ● MAIN has generated consistent growth in monthly dividends 109% increase from $0.33 per share in Q4 2007 to declared dividend of $0.69 per share for Q3 2023 MAIN has increased its monthly dividends every year from ● MAINST ● CAPITAL CORPORATION ● 2011 through 2022, excluding 2020 due to the impact of the COVID-19 pandemic Within the BDC Peer Group(1), 27 BDCs, or 84%, have decreased their regular dividend at least once since 2007 or their IPO date Of these 27, 16 BDCs, or 59%, have decreased their regular dividend multiple times since 2007 or their IPO date Earnings outperformance has resulted in supplemental dividends for the last seven consecutive quarters, providing shareholders with enhanced value NYSE: MAIN (1) BDC Peer Group includes dividend paying BDCs that have been publicly-traded for at least two years and have total assets greater than $500 million based on individual SEC Filings as of December 31, 2022, with the exception of NEWT, which is excluded due to the non-traditional nature of their business plan and operations compared to most BDCs and their change away from BDC election; see Appendix for details by BDC Main Street Capital Corporation mainstcapital.com#22MAIN's Strategy Consistently Produces Differentiated Returns MAIN has maintained a long-term consistent and growing Monthly Dividend that has been consistently and conservatively covered by earnings The Monthly Dividend growth for most BDCs in the Top 10% and Top Quartile has been recent (i.e. 2022) after years of limited historical growth 20.0% 15.0% 10.0% 5.0% 0.0% -5.0% -10.0% MAIN Monthly Dividend Growth (1¹)(2) 5-YR CAGR Top 10% 3-YR CAGR Top Quartile Middle Quartile NYSE: MAIN (3) Gross Div Potential 5-YR CAGR MAINST In addition, we believe that evaluating a BDC's total dividend potential in the current environment (by substituting NII for monthly dividends in 2022 as an indication of the total potential dividend growth (at a 100% dividend payout)) is a meaningful metric (1) Sources: Yearly dividends per share from individual company website; does not include supplemental dividends; see Appendix for details by BDC (2) Comparison columns include all BDCs includes all BDCs with total assets greater than $500 million as of December 31, 2022; see Appendix for details by BDC (3) Gross dividend potential CAGR is calculated by utilizing dividends per share for years 2017 through 2021 and NII per share for 2022 and represents the potential growth in dividends if dividends paid in 2022 matched NII for each BDC Main Street Capital Corporation mainstcapital.com CAPITAL CORPORATION Average Bottom Quartile Gross Div Potential 3-YR CAGR (3)#23MAIN's Strategy Consistently Produces Differentiated Returns MAIN ranks in the top quartile dividend coverage in 2022 MAIN's earnings have significantly outearned its monthly dividends, resulting in significant supplemental dividends The BDCs at the top quartile for monthly dividend growth (3 year and 5 year CAGR) rank at or below the bottom quartile in dividend coverage in 2022 130.0% 120.0% 110.0% 100.0% 90.0% 140.0% 130.0% 120.0% 110.0% 100.0% 90.0% 130.0% 120.0% 110.0% 100.0% 90.0% MAIN MAIN 2022 Dividend Coverage(1)(2)(3) Top 10% MAIN Top 10% Top Quartile Top 10% 2022 Dividend Coverage for the Monthly Dividend 5 Year CAGR quartiles (1)(2)(3)(4) Top Quartile Middle Quartile Top Quartile Middle Quartile Average Middle Quartile Average MAINST 2022 Dividend Coverage for the Monthly Dividend 3 Year CAGR Quartiles(1)(2)(3)(5) CAPITAL CORPORATION Average Bottom Quartile Bottom Quartile Bottom Quartile (1) Sources: Yearly dividends per share from individual company website; does not include supplemental dividends; see Appendix for details (2) Comparison columns include all BDCs includes all BDCs with total assets greater than $500 million as of December 31, 2022; see Appendix for details by BDC (3) 2022 Dividend NII Coverage is calculated as NII for 2022 divided by monthly dividends paid in 2022 (4) The peer group results represent the Dividend NII Coverage results for the respective BDCs in each of the quartiles for the monthly dividend growth 5 year CAGR (5) The peer group results represent the Dividend NII Coverage results for the respective BDCs in each of the quartiles for the monthly dividend growth 3 year CAGR Main Street Capital Corporation NYSE: MAIN mainstcapital.com#24MAIN's Strategy Consistently Produces Differentiated Returns Total Shareholder Returns are Better Indicator of Economic Value Creation for Shareholders MAIN has the highest Total Shareholder Return amongst its peer group - measured on both economic value and market value MAIN's Total Shareholder Return is 3 to 4 times higher than the peer group average and ~2 to 3 times higher than the top quartile 30.0% 25.0% T 20.0% 15.0% 10.0% 5.0% 0.0% 30.0% 25.0% 20.0% 15.0% 10.0% 5.0% 0.0% MAIN MAIN (4) Comparison columns include all BDCs noted in footnote (1) excluding MAIN Main Street Capital Corporation Total Shareholder Return - Economic Value(1)(2)(4) Top 10% Top 10% Top Quartile Total Shareholder Return - Market Value(¹)(3)(4) NYSE: MAIN Middle Quartile Top Quartile Peer Group Average Middle Quartile Peer Group Average MAINST CAPITAL CORPORATION (1) Source: Public Company filings; Appendix for detailed explanations of BDCs included in Peer Group and additional details on specific calculations (2) Calculation is (a) (i) Total NAV Change Plus Dividends Paid per Share divided by (ii) Beginning NAV divided by (b) number of years included in analysis (based upon IPO date) (3) Calculation is (a) (i) Total Market Price Change Plus Dividends Paid per Share divided by (ii) Beginning Market Price divided by (b) number of years included in analysis (based upon IPO date) Bottom Quartile Bottom Quartile mainstcapital.com#25MAIN's Return on Equity Compared to Industry Top GAAP ROE's Under RJ Coverage MAIN is the top performer on the key overall total return performance metric (GAAP Return on Equity, or ROE) MAIN'S GAAP ROE of 13.0% ranks #1 in the Raymond James' (RJ) coverage group ● ● Significant outperformance (-20% vs #2 ranked BDC) vs. BDCs with IPO dates in or before 2007 #1 overall for all BDCs despite MAIN experiencing impacts of the 2008/2009 Great Recession MAIN's Implied Credit Gains of 2.5% is well above the Industry average of an Implied Credit Loss of (1.3%) 14% 12% 10% 8% 6% 4% 2% 0% -2% Ticker Top 10% Top Quartile Middle Quartile Bottom Quartile Chart 15 - Historic Average GAAP ROE 4% 2% 10% MAIN FDUS TSLX W. Average -2% -4% -16% -8% -10% -12% Median ARCC BBDC W. Average Median BCSF ARCC BBDC BXSL BCSF ............... .............. LI Im dali Source: FactSet and Raymond James research. Chart 16 - Implied Credit Gains (Losses) GAAP ROE CCAP BXSL CGBD CCAP 13.0% 12.3% 12.0% 12.0% 9.5% 8.1% 6.6% CION CGBD CSWC CION FDUS FDUS CSWC FSK IPO Date 4Q 2007 2Q 2011 1Q 2014 FSK GBDC GBDC GLAD GSBD S ICMB GLAD MAIN ICMB GSBD MFIC MFIC MAIN Top 10% Top Quartile Middle Quartile Bottom Quartile OCSL NMFC OCSL NMFC Top GAAP ROE's Under RJ Coverage IPO Dates 2007 or prior Ticker GAAP ROE ORCC MAIN ARCC PSEC PELT ORCC PNNT PFLT PSEC PSEC PNNT SAR SAR SCM SCM SLRC TCPC SLRC TCPC MAINST CAPITAL CORPORATION 13.0% 11.0% 9.1% 13.0% 10.0% 6.9% 4.4% TSLX TSLX WHF WHF IPO Date 4Q 2007 4Q 2004 3Q 2004 Source: FactSet and Raymond James research. Note: Key Performance Metrics sourced from Raymond James' (RJ) June 2, 2023 Specialty Finance/ Business Development Companies 1Q23 ROE Quarterly Analysis; Select pages included in Appendix A Main Street Capital Corporation NYSE: MAIN mainstcapital.com#26Strategic Overview - Accomplishments MAIN's strategy has produced consistent results and returns MAIN continues to execute on the key aspects of its long-term plans as discussed in prior years MAIN is pleased with its accomplishments on its key objectives ● ● The following highlights several of MAIN's accomplishments over the last year: ● ● ● ● MAINST - CAPITAL CORPORATION Over the Last Year(1) Executed significant growth of our total Investment Portfolio (12.6%) to total investments of $3.8 billion Grew LMM investments by 14.1% to $1.7 billion Grew PL investments by 19.9% to $1.5 billion Executed growth of our assets under management (AUM) in our Asset Management Business (2) Grew AUM by 3.8% to $1.42 billion AMB provided significant benefits to MAIN(2) Improved our capital structure and liquidity position Generated GAAP Return on Equity of 12.8% Significantly increased the total Dividends paid to our shareholders, growing our Dividends by 18.1% to $0.85 per share in the first quarter of 2023(3) Increased our Monthly Dividends by 4.7% to $0.675 per share in the first quarter of 2023(3) Increased our Supplemental Dividends by 133.3% to $0.175 per share in the first quarter of 2023(³) Grew our NAV per share by $1.34, or 5.2%, to $27.23 per share (2) Through MSC Adviser I, LLC (the External Investment Manager), MAIN's wholly-owned unconsolidated subsidiary (3) In comparison to prior year Main Street Capital Corporation NYSE: MAIN (1) As applicable, represents either (a) information as of March 31, 2023, (b) growth from April 1, 2022 to March 31, 2023 or (c) results for the trailing twelve month period ended March 31, 2023 mainstcapital.com#27Strategic Overview - Accomplishments Over Last Year(¹) MAIN continues to execute on the key aspects of its long-term plans as discussed in prior years MAIN is pleased with its accomplishments on its key objectives Achieved significant growth of LMM investments ● Achieved significant growth of our LMM Investment Portfolio Continued focus on growth of new LMM investments Completed 4 new platform investments totaling $107.7 million ($120.4 million including amounts allocated to managed funds(2)) ● - MAINST CAPITAL CORPORATION Continued investment in existing portfolio companies - 9 LMM companies completed 14 follow on acquisitions - Total follow-on investments in existing LMM portfolio companies of $246.2 million ($285.7 million including amounts allocated to managed funds(²)) • Grew LMM portfolio by 14.1% ($214.1 million) on a cost basis and 17.7% ($317.1 million) at fair value; increased to 50.8% (from 48.6%) of total investment portfolio at fair value NYSE: MAIN (1) As applicable, represents either (a) information as of March 31, 2023, (b) growth from April 1, 2022 to March 31, 2023 or (c) results for the trailing twelve month period ended March 31, 2023, unless otherwise noted (2) MSC Income Fund, Inc., which is managed by MSC Adviser I, LLC (the External Investment Manager), MAIN's wholly owned unconsolidated registered investment adviser subsidiary Main Street Capital Corporation mainstcapital.com#28Strategic Overview - Accomplishments Over Last Year(¹) MAIN continues to execute on the key aspects of its long-term plans as discussed in prior years MAIN is pleased with its accomplishments on its key objectives Achieved significant growth of PL investments ● Achieved significant growth of our PL Investment Portfolio Continued focus on growth of new PL investments Completed 16 new portfolio company investments totaling $356.6 million ($462.2 million including amounts allocated to managed funds(2)) ● ● MAINST CAPITAL CORPORATION Significant follow-on investment activity in existing portfolio companies Total follow-on investments in existing PL portfolio companies of $198.5 million ($281.9 million including amounts allocated to managed funds(²)) Grew PL portfolio by 19.9% ($254.0 million) on a cost basis and 18.3% ($230.7 million) at fair value; increased to 35.8% (from 34.2%), of total Investment Portfolio at fair value (1) As applicable, represents either (a) information as of March 31, 2023, (b) growth from April 1, 2022 to March 31, 2023 or (c) results for the trailing twelve month period ended March 31, 2023, unless otherwise noted NYSE: MAIN (2) MSC Income Fund, Inc., MS Private Loan Fund I, and the Separately Managed Account, which are managed by MSC Adviser I, LLC (the External Investment Manager), MAIN'S wholly owned unconsolidated registered investment adviser subsidiary Main Street Capital Corporation mainstcapital.com#29MAIN's strategy has produced consistent results and returns Strategic Overview - Accomplishments Over the Last Year(¹) MAIN continues to execute on the key aspects of its long-term plan as discussed in prior years Achieved significant growth of its Asset Management Business (AMB) MAINST ● CAPITAL CORPORATION Achieved significant growth and success in our Asset Management Business Maintained MSC Income Fund, Inc. (MSIF) in a "fully invested" position and produced strong operating results ● Total Investment Portfolio of $1.06 billion (vs. $1.07 billion at March 31, 2022) Current dividend rate of $0.70 per share equals highest payment rate in MSIF's history Generating significant Incentive fees to MAIN ($4.9 million) Grew investment portfolio at MS Private Loan Fund I, LP and produced strong operating results Grew total Investment Portfolio by 58.7% to $175.8 million Current distributions to limited partner investors at or above the high-end of original expectations • Grew total Management fees to MAIN(2) by 40.6% Base Management Fees grew by 14.0% to $21.8 million Incentive Fees grew by 691.7% to $5.7 million Expect to earn continued Incentive Fees for the near-term foreseeable future (1) As applicable, represents either (a) information as of March 31, 2023, (b) growth from April 1, 2022 to March 31, 2023 or (c) results for the trailing twelve month period ended March 31, 2023 (2) Through MSC Adviser I, LLC (the External Investment Manager), MAIN's wholly-owned unconsolidated subsidiary Main Street Capital Corporation NYSE: MAIN mainstcapital.com#30MAIN continues to execute on the key aspects of its long-term plans as discussed in prior years Strategic Overview - Accomplishments Over the Last Year MAIN is pleased with its accomplishments on its key objectives Expanded and diversified its debt financing relationships Maintained conservative capital structure and liquidity position (1) As of March 31, 2023 Main Street Capital Corporation ● Maintained strengths of capital structure and liquidity position Maintained investment grade debt ratings by S&P Global Ratings and Fitch Ratings ● MAINST ● CAPITAL CORPORATION - S&P reaffirmed BBB-/Stable Fitch Ratings reaffirmed BBB-/Stable Expanded and diversified debt financing relationships Increased total commitments on our Corporate Facility to $980.0 million Entered into a new SPV Facility which includes $255.0 million in capacity due November 2027 - Issued $150 million of Series A/B unsecured notes due in December 2025 Continued effective use of low cost and efficient at-the-market (ATM) equity offerings to maintain optimal liquidity and conservative leverage position Maintained conservative leverage profile: Debt to Equity Ratio of 0.92x(1) Non-SBIC Debt to Equity Ratio of 0.77x(1) NYSE: MAIN From March 31, 2022 to March 31, 2023, MAIN raised net proceeds of $187.7 million through ATM equity offerings at an average issue price premium to NAV per share of approximately 50%; Supplemented with an equity offering resulting in net proceeds of $55.1 million Maximize utilization of attractive SBIC debentures MAIN enjoys total SBIC debenture regulatory financing capacity(¹) of $350.0 million, the maximum amount permitted under current U.S. Small Business Administration (SBA) regulations mainstcapital.com#31MAIN continues to execute on the key aspects of its long-term plans as discussed in prior years Strategic Overview - Accomplishments Over the Last Year MAIN is pleased with its accomplishments on its key objectives (2) In comparison to prior year (3) Dividends declared and paid as of June 23, 2023 Main Street Capital Corporation ● MAIN continued to generate best-in-class returns and provided significant benefits to our shareholders ● ● ● ● ● MAINST CAPITAL CORPORATION Grew DNII by 32.2% for the year ended 2022 and 56.3% for the quarter ended March 31, 2023 (²) Generated DNII per share in excess of Monthly Dividends per share by 33.3% for the year ended 2022 and 58.5% for the quarter ended March 31, 2023 Maintained conservative dividend policy with DNII per share exceeding Total Dividends (Monthly and Supplemental) per share by 17.5% for the year ended 2022 and 25.9% for the quarter ended March 31, 2023 Have now declared and paid seven consecutive quarterly Supplemental Dividends (totaling $0.85 per share) out of the excess DNII above the - Monthly Dividends for each quarter from the fourth quarter of 2021 through the second quarter of 2023(³) Grew NAV per share by 6.2% during 2022 and 1.4% in Q1 2023 Return on Equity of 12.6% during 2022 and 14.9% (on an annualized basis) for the first quarter of 2023 Grew Total Dividends to shareholders by 14.7% to $3.075 per share(1) Grew Monthly Dividends by 4.8% to $2.625 per share(1) Grew Supplemental Dividends by 157.1% to $0.45 per share(¹) (1) As applicable, represents either (a) information as of March 31, 2023, (b) growth from April 1, 2022 to March 31, 2023 or (c) results for the trailing twelve month period ended March 31, 2023 NYSE: MAIN mainstcapital.com#32MAIN's strategy has produced consistent results and returns Strategic Overview - Accomplishments Over the Last Year(¹) MAIN continues to execute on the key aspects of its long-term plan as discussed in prior years MAIN is pleased with its accomplishments on its key objectives ● MAINST CAPITAL CORPORATION Our positive operating results from the last few quarters have generated and are expected in the future to continue to generate "best in class" returns and shareholder benefits - Prior guidance for the second quarter 2023 included an expectation for DNII per share of $0.95, with the opportunity to exceed this level of performance As of today, based up on the benefits of the continued positive performance of our Investment Portfolio, impacts of the current interest rate environment and continued benefits from our Asset Management Business, we expect DNII per share for the second quarter of 2023 to be consistent with or greater than the $1.07 per share of DNII for the first quarter of 2023 (1) Based upon current operating results and expectations as of June 22, 2023 Main Street Capital Corporation - In addition, given the continued positive performance we also reconfirm our prior guidance that we anticipate proposing an additional supplemental dividend to our Board of Directors for the third quarter of 2023, with this supplemental dividend expected to be equal to or greater than our June 2023 supplemental dividend of $0.225 per share NYSE: MAIN mainstcapital.com#33MAIN's Total Return(1) Performance Since IPO $1200 $1000 $800 $600 $400 $200 $0 2008 2009 2010 TOTAL RETURN PERFORMANCE SINCE MAIN IPO 2011 2012 (2) MAIN (855.96%) S&P BDC Index (-54.52%) (4) 2013 2014 Amma 2015 S&P 500 (261.00%) 2016 2017 2018 Russell 2000 (163.71%) 2019 NYSE: MAIN 2020 2021 2022 MAINST CAPITAL CORPORATION 2023 KBW Regional Bank Index (-0.29%) (3) $1200 $1000 $800 $600 $400 $200 $0 Notes: (1) Assumes dividends reinvested on date paid (2) Indexed as of October 5, 2007 and last trading date is March 31, 2023 (3) The KBW Nasdaq Regional Banking Index is a modified market capitalization weighted index designed to track the performance of U.S. regional banks or thrifts that are publicly traded in the U.S. (4) The S&P BDC Index measures the performance of Business Development Companies that trade on major U.S. exchanges; Constituents are float-adjusted market capitalization (FMC) weighted, subject to a single constituent weight cap of 10% Main Street Capital Corporation mainstcapital.com#34Main Street Capital Corporation Appendix Main Street Capital Corporation NYSE: MAIN MAINST CAPITAL CORPORATION mainstcapital.com#35Dividend Paying BDCs Public for > 2 Years (3) MAIN Maintains a Significant Operating Cost Advantage BDC Manager Costs Relative to Total Economic Benefit Generated (dollars in thousands) 5 Year Total(¹)(2) Main Street Capital Corporation Peer Group Average (4) Peer Group Top 10%(4) Peer Group Top Quartile(4) Peer Group Middle Quartile (4 Peer Group Bottom Quartile (4 Net Increase in Net Assets (ie. Net Income) $ 899,533 Add back: Compensation and Mgmt Fees $ 151,060 Gross Economic Beneft Before Management Costs $ MAINST 1,050,593 CAPITAL CORPORATION % Economic Profits Paid to Management 14.4% 37.3% 22.6% 29.9% 35.1% 41.8% (1) Source: Public company filings (2) Amounts represent the total for the most recent five trailing twelve month periods through December 31, 2022 for each respective company; for each applicable BDC not > 5 years past IPO, the first full fiscal year-end post-IPO was used as the starting point for this analysis; see details by BDC on the following pages (3) BDC Peer Group includes dividend paying BDCs that have been publicly-traded for at least two years and have total assets greater than $500 million based on individual SEC Filings as of December 31, 2022, with the exception of NEWT, which is excluded due to the non-traditional nature of their business plan and operations compared to most BDCs and their change away from BDC election; see details by BDC on the following pages (4) Comparison columns include all BDCs noted in footnote (3) excluding (a) MAIN and (b) a BDC that had a net decrease in net assets and which would significantly affect the Peer Group comparisons; as an example, the Average would be 56.7% including the BDC with a net decrease in net assets; see details by BDC on the following page Main Street Capital Corporation NYSE: MAIN mainstcapital.com#36Dividend Paying BDCs Public for >2 Years (3) MAIN Maintains a Significant Operating Cost Advantage BDC Manager Costs Relative to Total Economic Benefit Generated (dollars in thousands) Main Street Capital Corporation Ares Capital Corporation Barings BDC, Inc. Bain Capital Specialty Finance Inc. BlackRock Capital Investment Corporation (4) Crescent Capital BDC, Inc. TCG BDC, Inc. Capital Southwest Corporation Fidus Investment Corporation FS KKR Capital Corp Gladstone Investment Corporation Golub Capital BDC, Inc. Gladstone Capital Corporation Goldman Sachs BDC, Inc. Horizon Technology Finance Corporation Hercules Capital, Inc. MidCap Financial Investment Corporation M ment Structure Internal External External External External External External Internal External External External External External External External Internal External Net Increase in Net Assets (ie. Net Income) $ 899,533 4,302,000 34,453 331,650 (49,927) 191,243 353,264 143,712 281,070 2,017,000 279,813 611,983 140,857 513,369 87,805 753,591 181,951 5 Year Total(¹)(2) Add back: Compensation and Mgmt Fees $ 151,060 2,185,000 137,478 179,272 58,901 44,127 250,259 52,510 129,948 928,000 111,777 297,962 23,287 147,211 63,089 224,539 232,977 Gross Economic Benefit Before Management Costs $ MAINST 1,050,593 6,487,000 171,931 510,922 8,974 235,370 603,523 196,222 411,018 2,945,000 391,590 909,945 164,144 660,580 150,894 978,130 414,928 CAPITAL CORPORATION % Economic Profits Paid Management 14.4% 33.7% 80.0% 35.1% N/A 18.7% 41.5% 26.8% 31.6% 31.5% 28.5% 32.7% 14.2% 22.3% 41.8% 23.0% 56.1% (1) Source: Public company filings (2) Amounts represent the total for the most recent five trailing twelve month periods through December 31, 2022 for each respective company; for each applicable BDC not > 5 years past IPO, the first full fiscal year-end post-IPO was used as the starting point for this analysis as follows: BCSF - 2019 and ORCC - 2020 (3) BDC Peer Group includes dividend paying BDCs that have been publicly-traded for at least two years and have total assets greater than $500 million based on individual SEC Filings as of December 31, 2022, with the exception of NEWT, which is excluded due to the non-traditional nature of their business plan and operations compared to most BDCs and their change away from BDC election (4) Excluded from Peer Group Average as the company had a net decrease in net assets which would significantly affect the overall average calculation Main Street Capital Corporation NYSE: MAIN mainstcapital.com#37BDCs Dividend Public for > 2 Years (3) Main Street Capital Corporation Monroe Capital Corporation New Mountain Finance Corporation Oaktree Specialty Lending Corporation OFS Capital Corporation Owl Rock Capital Corp MAIN Maintains a Significant Operating Cost Advantage (cont.) BDC Manager Costs Relative to Total Economic Benefit Generated (dollars in thousands) Pennant Park Floating Rate Capital Ltd. Pennant Park Investment Corporation Prospect Capital Corporation Portman Ridge Finance Corporation Saratoga Investment Corp. Stellus Capital Investment Corporation Solar Capital Ltd. Blackrock TCP Capital Corp. Triple Point Venture Growth BDC Corp. TPG Specialty Lending, Inc. WhiteHorse Finance, Inc. Management Structure Internal External External External External External External External External Internal External External External External External External External Net Increase in Net Assets (ie. Net Income) 899,533 56,381 519,520 $ 478,629 72,097 2,179,221 123,288 189,545 1,974,517 33,675 152,439 120,887 216,249 271,996 160,115 771,541 165,604 5 Year Total(¹)(2) NYSE: MAIN Add back: Compensation and Mgmt Fees $ 151,060 59,968 333,817 233,249 53,218 883,929 87,466 112,593 1,043,658 41,475 81,911 86,796 198,757 220,281 98,635 328,835 108,608 Gross Economic Benefit Before Management Costs $ MAIN ST 1,050,593 116,349 853,337 711,878 125,315 3,063,150 210,754 302,138 3,018,175 75,150 234,351 207,683 415,006 492,277 258,750 1,100,376 274,212 CAPITAL CORPORATION % Economic Profits Paid to Management 14.4% 51.5% 39.1% 32.8% 42.5% 28.9% 41.5% 37.3% 34.6% 55.2% 35.0% 41.8% 47.9% 44.7% 38.1% 29.9% 39.6% (1) Source: Public company filings (2) Amounts represent the total for the most recent five prior trailing twelve month periods through December 31, 2022 for each respective company; for each applicable BDC not > 5 years past IPO, the first full fiscal year-end post-IPO was used as the starting point for this analysis as follows: BCSF - 2019 and ORCC - 2020 (3) BDC Peer Group includes dividend paying BDCs that have been publicly-traded for at least two years and have total assets greater than $500 million based on individual SEC Filings as of December 31, 2022, with the exception of NEWT, which is excluded due to the non-traditional nature of their business plan and operations compared to most BDCs and their change away from BDC election Main Street Capital Corporation mainstcapital.com#38MAIN's Strategy Consistently Produces Differentiated Returns Historical Monthly Dividend Growth and Coverage of Monthly Dividends with Earnings (1)(2) Dividend Paying BDCs Public for > 5 Years (2) Main Street Capital Corporation Peer Group Average Peer Group Top 10% Peer Group Top Quartile Peer Group Middle Quartile Peer Group Bottom Quartile NE 2017 $2.24 (3) Monthly Dividends Per Share 2018 2019 2020 $2.30 $2.42 $2.46 2021 $2.48 2022 $2.60 NII Per Share 5-YR 3-YR CAGR CAGR 2022 $3.29 3.0% 2.4% 1.6% 0.1% 9.0% 15.6% 3.4% 4.6% -0.4% 0.0% -5.3% -4.3% Gross Div Potential 5-YR CAGR (3) 8.0% 2.6% 12.1% 6.1% 2.0% -2.1% Gross Div Potential 3-YR CAGR (3) 10.9% 5.9% 18.4% 10.5% 3.6% -1.6% (4) MAINST Coverage 126.8% 114.2% 133.1% 124.7% 115.7% 101.7% CAPITAL CORPORATION Coverage Monthly Div Growth 5-YR (4)(5) CAGR 126.8% 114.2% 121.8% 101.8% 117.8% 144.3% (1) Sources: Yearly dividends per share from individual company website; does not include supplemental dividends; see details on following pages Comparison columns include all BDCs includes all BDCs with total assets greater than $500 million as of December 31, 2022; see details on following pages Gross dividend potential CAGR is calculated by utilizing dividends per share for years 2017 through 2021 and NII per share for 2022 and represents the potential growth in dividends if dividends paid in 2022 matched NII for each BDC (4) 2022 Dividend NII Coverage calculated as NII for 2022 divided by monthly dividends paid in 2022 (5) The peer group results represent the Dividend NII Coverage results for the respective BDCs in each of the quartiles for the monthly dividend growth 5 year CAGR (6) The peer group results represent the Dividend NII Coverage results for the respective BDCs in each of the quartiles for the monthly dividend growth 3 year CAGR Main Street Capital Corporation NYSE: MAIN mainstcapital.com Coverage Monthly Div Growth 3-YR CAGR (4)(6) 126.8% 114.2% 107.0% 94.7% 118.5% 121.7%#39Dividend Paying BDCs Public for > 5 Years (2) MAIN's Strategy Consistently Produces Differentiated Returns Historical Monthly Dividend Growth and Coverage of Monthly Dividends with Earnings (1)(2) Gross Div Potential 5-YR Gross Div Potential 3-YR CAGR (4) CAGR (4) Main Street Capital Corporation Ares Capital Corporation Barings BDC, Inc. BlackRock Capital Investment Corporation Crescent Capital BDC, Inc. Carlyle Secured Lending Capital Southwest Corporation Fidus Investment Corporation FS KKR Capital Corp Gladstone Investment Corporation Gladstone Capital Corporation Goldman Sachs BDC, Inc. Golub Capital BDC, Inc. Horizon Technology Finance Corporation Hercules Capital, Inc. Mid Cap Financial Investment Corporation 2017 $2.24 1.52 1.65 0.75 1.14 1.56 0.88 1.56 0.89 0.77 0.84 1.80 1.28 1.20 1.24 1.80 2018 $2.30 1.54 0.43 0.72 1.38 1.48 1.53 1.56 0.76 0.80 0.84 1.80 1.28 1.20 1.24 1.80 Monthly Dividends Per Share (3) 2019 $2.42 1.60 0.54 0.64 1.63 1.48 1.57 1.56 0.76 0.82 0.84 2.25 1.29 1.20 1.27 1.80 2020 $2.46 1.60 0.65 0.44 1.64 1.43 1.64 1.29 1.58 0.91 0.80 1.35 1.20 1.20 1.28 1.52 2021 $2.48 1.62 0.82 0.40 1.64 1.28 1.76 1.26 2.45 0.86 0.78 1.80 1.17 1.20 1.29 1.24 2022 $2.60 1.75 0.95 0.40 1.64 1.30 1.98 1.44 2.54 0.92 0.81 1.80 1.23 1.20 1.37 1.31 NII Per Share 2022 $3.29 2.19 1.07 0.40 1.93 2.00 1.63 1.90 3.05 1.03 0.92 2.24 1.25 1.46 1.50 1.58 5-YR CAGR 3.03% 2.86% -10.45% -11.81% 7.54% -3.58% 17.61% -1.59% 23.31% 3.61% -0.72% 0.00% -0.79% 0.00% 2.01% -6.16% 3-YR CAGR 2.43% 3.03% 20.72% -14.50% 0.20% -4.23% 8.04% -2.63% 49.51% 3.89% -1.20% -7.17% -1.58% 0.00% 2.56% -10.05% MAINST 8.04% 7.60% -8.27% -11.79% 11.15% 5.06% 13.10% 4.05% 27.91% 6.00% 1.86% 4.43% -0.53% 4.05% 3.91% -2.63% CAPITAL CORPORATION 10.86% 11.08% 25.67% -14.46% 5.86% 10.49% 1.23% 6.84% 58.93% 7.92% 3.11% -0.22% -1.14% 6.84% 5.76% -4.35% Coverage 126.9% 125.3% 118.3% 100.2% 117.9% 153.6% 108.0% 132.1% 120.1% 112.1% 113.7% 124.2% 101.3% 122.0% 109.7% 120.2% (1) Sources: Yearly dividends per share from individual company website; does not include supplemental dividends (2) BDC Peer Group includes dividend paying BDCs that have been publicly-traded for at least two years and have total assets greater than $500 million based on individual SEC Filings as of December 31, 2022, with the exception of NEWT, which is excluded due to the non-traditional nature of their business plan and operations compared to most BDCs and their change away from BDC election (3) Certain BDC' historical dividends have been adjusted for subsequent reverse stock splits: MFIC-2018; FSK - 2020; PTMN - 2021; and OCSL - 2022 (4) Gross dividend potential CAGR is calculated by utilizing dividends per share for years 2017 through 2021 and NII per share for 2022 and represents the potential growth in dividends if dividends paid in 2022 matched NII for each BDC (5) 2022 Dividend NII Coverage is calculated as NII for 2022 divided by monthly dividends paid in 2022 Main Street Capital Corporation NYSE: MAIN mainstcapital.com#40MAIN's Strategy Consistently Produces Differentiated Returns (cont.) Dividend Paying BDCs Public for > 5 Years (2) Main Street Capital Corporation Monroe Capital Corporation New Mountain Finance Corporation Oaktree Specialty Lending Corporation OFS Capital Corporation Pennant Park Floating Rate Capital Ltd. PennantPark Investment Corp. Prospect Capital Corporation Portman Ridge Finance Corporation Saratoga Investment Corp Stellus Capital Investment Corporation Solar Capital Ltd. Historical Monthly Dividend Growth and Coverage of Monthly Dividends with Earnings (1)(2) Gross Div Potential 5-YR CAGR(4) Gross Div Potential 3-YR CAGR (4) 10.86% -9.89% -4.26% 30.68% 0.19% 0.65% -4.12% 10.53% -2.14% 6.22% 2.53% -3.41% 2.06% 10.52% 10.89% 4.14% BlackRock TCP Capital Corp. TriplePoint Venture Growth BDC Corp. TPG Specialty Lending, Inc. WhiteHorse Finance, Inc. 2017 $2.24 1.40 1.36 1.23 1.36 1.14 0.82 0.93 4.80 2.35 1.36 1.60 1.44 1.44 1.56 1.42 2018 $2.30 1.40 1.36 1.11 1.73 1.14 0.72 0.72 4.00 1.53 1.36 1.63 1.44 1.44 1.56 1.42 Monthly Dividends Per Share (3) 2020 $2.46 1.10 1.24 1.22 0.86 1.14 0.54 0.72 2.40 1.37 1.26 1.64 1.32 2019 $2.42 1.40 1.36 1.14 1.36 1.14 0.72 0.72 3.20 2.18 1.36 1.64 1.44 1.44 1.56 1.42 1.44 1.62 1.42 2021 $2.48 1.00 1.20 1.65 0.91 1.14 0.48 0.72 2.42 1.81 1.08 1.64 1.20 1.44 1.64 1.42 2022 $2.60 1.00 1.22 2.03 1.16 1.14 0.56 0.72 2.56 2.13 1.60 1.91 1.22 1.45 2.10 1.42 NII Per Share 2022 $3.29 1.02 1.19 2.54 1.37 1.16 0.63 0.97 3.00 2.61 1.46 1.48 1.53 1.94 2.13 1.60 5-YR CAGR 3.03% -6.51% -2.15% 10.49% -3.13% 0.00% -7.51% -4.98% -11.81% -1.95% 3.26% 3.64% -3.26% 0.14% 6.13% 0.00% MAIN ST 3-YR CAGR 2.43% -10.61% -3.56% 21.11% -5.16% 0.00% -8.31% 0.00% -7.17% -0.77% 5.57% 5.27% -5.38% 0.23% 10.42% 0.00% CAPITAL CORPORATION -1.58% 1.23% 6.19% 6.40% 2.47% 8.04% -6.06% -2.58% 15.64% 0.11% 0.39% -5.00% 0.90% -8.98% 2.14% 1.46% (3) Certain BDC' historical dividends have been adjusted for subsequent reverse stock splits: MFIC - 2018; FSK - 2020; PTMN - 2021; and OCSL - 2022 (4) Gross dividend potential CAGR is calculated by utilizing dividends per share for years 2017 through 2021 and NII per share for 2022 and represents the potential growth in dividends if dividends paid in 2022 matched NII for each BDC (5) 2022 Dividend NII Coverage is calculated as NII for 2022 divided by monthly dividends paid in 2022 Main Street Capital Corporation NYSE: MAIN Coverage 126.8% 102.4% 97.8% 125.6% 117.9% 102.0% 114.3% (1) Sources: Yearly dividends per share from individual company website; does not include supplemental dividends BDC Peer Group includes dividend paying BDCs that have been publicly-traded for at least two years and have total assets greater than $500 million based on individual SEC Filings as of December 31, 2022, with the exception of NEWT, which is excluded due to the non-traditional nature of their business plan and operations compared to most BDCS and their change away from BDC electic (5) 135.0% 117.1% 122.6% 91.6% 77.2% 125.5% 134.1% 101.3% 113.0% mainstcapital.com#41MAIN's Strategy Consistently Produces Differentiated Returns Dividend Paying BDCs Public (1) for > 2 Years Total Shareholder Returns are Better Indicator of Economic Value Creation for Shareholders Main Street Capital Corporation Peer Group Average Peer Group Top 10% Peer Group Top Quartile Peer Group Middle Quartile Peer Group Bottom Quartile Net Asset Value Per Share (2)(3) Beg 13.06 Total Shareholder Return - Economic Value NAV Change Plus Div Per Share 44.17 Inc (Dec) in NAV Per Share Dividends Paid Per Share 2011-2022 (3)(4) 13.80 30.37 12/31/22 26.86 Avg Ann'l Return as a % of Beg NAV (5) 28.2% 7.3% 13.3% 9.4% 7.7% 5.0% Closing Trading Price Per Share (2)(3) 12/31/22 36.95 MAINST Beg 18.19 NYSE: MAIN CAPITAL CORPORATION Total Shareholder Return - Market Value Inc (Dec) Dividends Mkt Price Chg in Market Paid Per Share Plus Div Price 2011-2022 (3) (4) Per Share 18.76 30.37 49.13 Avg Ann'l Return as a % (6) Beg Mkt Price 22.5% 7.0% 16.1% 10.0% 6.3% 3.3% (1) BDC Peer Group includes dividend paying BDCs that have been publicly-traded for at least two years and have total assets greater than $500 million based on individual SEC Filings as of December 31, 2022, with the exception of NEWT, which is excluded due to the non-traditional nature of their business plan and operations compared to most BDCs and their change away from BDC election; see details by BDC on the following pages Represents either (a) 12/31/10 if BDC has been public > 12 years or (b) the first 12/31 date after IPO date. For each applicable BDC not > 12 years past IPO, the beginning 12/31 period is provided for each applicable on the following pages (2) (3) Certain BDC's beginning NAV, share price, and dividends have been adjusted for subsequent reverse stock splits; see the details for each applicable BDC in the Appendix (4) Represents either (a) dividends for full 12 years if BDC ha been public > 12 years or (b) dividends from first full 12/31 calendar year-end after IPC through 12/31/22; see details by BDC on the following page (5) Calculation is (a) (i) Total NAV Change Plus Dividends Paid per Share divided by (ii) Beginning NAV divided by (b) number of years included in analysis (based upon IPO date) (6) Calculation is (a) (i) Total Market Price Change Plus Dividends Paid per Share divided by (ii) Beginning Market Price divided by (b) number of years included in analysis (based upon IPO date) Main Street Capital Corporation mainstcapital.com#42MAIN's Strategy Consistently Produces Differentiated Returns Dividend Paying BDCs Public for >2 Years (¹) Total Shareholder Returns are Better Indicator of Economic Value Creation for Shareholders Total Shareholder Return - Market Value Increase Dividends (Decrease) in Paid Per Share (3) (4) Market Price 2011-2022 18.76 30.37 1.49 19.07 (10.85) 19.58 (4.56) 7.69 (7.44) 9.15 (1.80) 14.01 (1.79) 10.37 7.57 14.30 17.88 6.06 (22.22) 5.26 10.76 9.55 9.95 12.75 Main Street Capital Corporation Ares Capital Corporation Barings BDC, Inc. Bain Capital Specialty Finance Inc. BlackRock Capital Investment Corporation BlackRock TCP Capital Corp. Crescent Capital BDC, Inc. Capital Southwest Corporation Fidus Investment Corporation FS KKR Capital Corp Gladstone Investment Corporation Gladstone Capital Corporation Goldman Sachs BDC, Inc. Golub Capital BDC, Inc. Horizon Technology Finance Corporation Hercules Capital, Inc. MidCap Financial Investment Corporation Net Asset Value Per Share (2)(3) Beg 12/31/22 13.06 26.86 14.92 18.40 12.09 11.05 20.10 17.29 9.62 4.39 14.71 12.93 19.13 19.83 34.23 16.25 14.90 19.43 39.32 9.00 11.74 18.97 14.74 16.75 9.50 29.19 24.89 13.43 9.06 14.61 14.71 11.47 10.53 15.10 Total Shareholder Return - Economic Value Dividends Paid Per Share (3) (4) 2011-2022 30.37 19.07 19.58 7.69 9.15 14.01 10.37 14.30 17.88 10.76 9.55 9.95 12.75 15.71 15.85 15.39 25.32 Increase (Decrease) in NAV Per Share 13.80 3.48 (1.04) (2.81) (5.23) (1.78) 0.70 (17.98) 4.53 (14.43) 4.43 (2.68) (4.36) (0.03) (5.28) 1.03 (14.09) NAV Change Plus Div Per Share 44.17 22.55 18.54 4.88 3.92 12.23 11.07 (3.68) 22.41 (3.67) 13.98 7.27 8.39 15.68 10.57 16.42 11.23 Avg Ann'l Return as a % (5) of Beg NAV 28.2% 12.6% 12.8% 4.0% 3.4% 8.3% 8.3% -0.9% 13.7% -1.2% 12.9% 5.2% 7.4% 8.9% 5.3% 14.4% 3.2% Closing Trading Price Per Share (2)(3) 12/31/22 36.95 17.97 8.15 11.90 3.62 12.94 12.78 17.10 19.03 17.50 12.91 9.62 13.72 13.16 11.60 13.22 11.40 Beg 18.19 16.48 19.00 16.46 11.06 14.74 14.57 NYSE: MAIN 9.53 12.97 39.72 7.65 11.52 19.00 17.12 14.44 10.36 33.21 (1.90) (5.28) (3.96) (2.84) 2.86 (21.81) MAINST 15.71 15.85 15.39 25.32 CAPITAL CORPORATION Mkt Price Chg Plus Div Per Share 49.13 20.56 8.73 3.13 1.71 12.21 8.58 21.87 23.94 (11.46) 14.81 8.05 7.47 11.75 13.01 18.25 3.51 Avg Ann'l Return as a % (6) Beg Mkt Price 22.5% 10.4% 3.8% 3.2% 1.3% 8.3% 8.4% 19.1% 16.8% -3.6% 16.1% 5.8% 6.6% 5.7% 7.5% 14.7% 0.9% (1) BDC Peer Group includes dividend paying BDCs that have been publicly-traded for at least two years and have total assets greater than $500 million based on individual SEC Filings as of December 31, 2022, with the exception of NEWT, which is excluded due to the non-traditional nature of their business plan and operations compared to most BDCS and their change away from BDC election (2) Represents either (a) 12/31/10 if BDC has been public > 12 years or (b) the first 12/31 date after IPO date. For each applicable BDC not > 12 years past IPO, the beginning 12/31 period is as follows: BCSF - 2017; CCAP - 2015; CGBD-2014; CSWC-2013; FSK-2014; GAIN-2016; GSBD-2016; MRCC-2012; OFS - 2012; ORCC - 2019; PFLT-2012; SCM - 2012; TCPC-2012; TPVG - 2014; TSLX - 2014; and WHF - 2012 (3) Certain BDC's beginning NAV, share price, and dividends have been adjusted for subsequent reverse stock splits: MFIC - 2018; FSK-2020; PTMN - 2021; and OCSL - 2022 (4) Represents either (a) dividends for full 12 years if BDC has been public > 12 years or (b) dividends from first full 12/31 calendar year-end after IPO date through 12/31/22; See footnote (2) above for details (5) Calculation is (a) (i) Total NAV Change Plus Dividends Paid per Share divided by (ii) Beginning NAV divided by (b) number of years included in analysis (based upon IPO date) (6) Calculation is (a) (i) Total Market Price Change Plus Dividends Paid per Share divided by (ii) Beginning Market Price divided by (b) number of years included in analysis (based upon IPO date) Main Street Capital Corporation mainstcapital.com#43Dividend Paying BDCs Public for > 2 Years (1) MAIN's Strategy Consistently Produces Differentiated Returns (cont.) Total Shareholder Returns are Better Indicator of Economic Value Creation for Shareholders Total Shareholder Return - Market Value Increase Dividends (Decrease) in Paid Per Share (3) (4) Market Price 2011-2022 18.76 30.37 (6.29) 12.82 (1.04) 15.13 10.61 12.65 4.26 12.16 10.51 11.62 70.38 25.33 13.52 21.26 14.08 11.73 16.58 14.46 Main Street Capital Corporation Monroe Capital Corporation New Mountain Finance Corporation Oaktree Specialty Lending Corporation OFS Capital Corporation Owl Rock Capital Corp Pennant Park Floating Rate Capital Ltd. PennantPark Investment Corp. Prospect Capital Corporation Portman Ridge Finance Corporation Saratoga Investment Corp. Stellus Capital Investment Corporation Solar Capital Ltd. TCG BDC, Inc. TriplePoint Venture Growth BDC Corp. TPG Specialty Lending, Inc. WhiteHorse Finance, Inc. Net Asset Value Per Share (2)(3) Beg 12/31/22 13.06 26.86 14.54 10.39 13.60 13.02 31.32 19.63 14.80 13.47 14.85 14.99 13.68 11.14 10.25 82.10 24.95 14.45 22.73 19.05 14.61 15.53 15.30 11.30 7.71 9.94 24.23 28.25 14.02 18.33 16.99 11.88 16.48 14.30 Total Shareholder Return - Economic Value Dividends Paid Per Share 2011-2022 (3)(4) 30.37 Increase (Decrease) in NAV Per Share 13.80 (4.15) (0.58) (11.69) (1.33) 0.14 (2.38) (3.43) (0.31) (57.87) 3.30 (0.43) (4.40) (2.06) (2.73) 0.95 (1.00) 12.82 15.13 10.61 12.65 4.26 12.16 10.51 11.62 70.38 25.33 13.52 21.26 14.08 11.73 16.58 14.46 NAV Change Plus Div Per Share 44.17 8.67 14.55 (1.08) 11.32 4.40 9.78 7.08 11.31 12.51 28.63 13.09 16.86 12.02 9.00 17.53 13.46 Avg Ann'l Return as a % of Beg NAV (5) 28.2% 6.0% 9.7% -0.3% 7.6% 4.9% 6.5% 5.3% 9.2% 1.3% 9.6% 9.1% 6.2% 9.0% 7.7% 14.1% 8.8% Closing Trading Price Per Share (2)(3) Beg 12/31/22 18.19 36.95 14.83 8.54 13.41 12.37 36.42 20.61 13.69 10.15 17.89 11.55 10.98 5.75 6.99 23.00 25.49 13.26 13.91 14.31 10.43 17.80 13.05 10.30 12.25 10.80 69.70 17.35 16.31 24.78 20.04 14.85 16.82 14.81 (15.81) (3.54) (6.34) 0.68 (6.50) (3.81) NYSE: MAIN (46.70) 8.14 MAINST (3.05) (10.87) (5.73) (4.42) 0.98 (1.76) CAPITAL CORPORATION Mkt Price Chg Plus Div Per Share 49.13 6.53 14.09 (5.20) 9.11 (2.08) 12.84 4.01 7.81 23.68 33.47 10.47 10.39 8.35 7.31 17.56 12.70 Avg Ann'l Return as a % (6) Beg Mkt Price 22.5% 4.4% 9.6% -1.2% 6.7% -1.9% 11.3% 2.7% 6.0% 2.8% 16.1% 6.4% 3.5% 6.0% 6.2% 13.0% 8.6% (1) BDC Peer Group includes dividend paying BDCs that have been publicly-traded for at least two years and have total assets greater than $500 million based on individual SEC Filings as of December 31, 2022, with the exception of NEWT, which is excluded due to the non-traditional nature of their business plan and operations compared to most BDCs and their change away from BDC election (2) Represents either (a) 12/31/10 if BDC has been public > 11 years or (b) the first 12/31 date after IPO date. For each applicable BDC not > 11 years past IPO, the beginning 12/31 period is as follows: BCSF - 2017; CCAP - 2015; CGBD 2014; CSWC-2013; FSK-2014; GAIN-2016; GSBD-2016; MRCC-2012; OFS - 2012; ORCC - 2019; PFLT-2012; SCM-2012; TCPC - 2012; TPVG - 2014; TSLX - 2014; and WHF - 2012 Certain BDC's beginning NAV, share price, and dividends have been adjusted for subsequent reverse stock splits: MFIC - 2018; FSK - 2020; PTMN - 2021; and OCSL - 2022 (4) Represents either (a) dividends for full 12 years if BDC has been public > 12 years or (b) dividends from first full 12/31 calendar year-end after IPO date through 12/31/22; See footnote (2) above for details (5) Calculation is (a) (i) Total NAV Change Plus Dividends Paid per Share divided by (ii) Beginning NAV divided by (b) number of years included in analysis (based upon IPO date) (6) Calculation is (a) (i) Total Market Price Change Plus Dividends Paid per Share divided by (ii) Beginning Market Price divided by (b) number of years included in analysis (based upon IPO date) Main Street Capital Corporation mainstcapital.com#44Ⓡ S G GAMBER JOHNSON Main Street Capital Corporation Brian Wagner CEO S GAMBER PMT zirkona PREMIER MOUNTS InfoCase LIND Gautam Malik President and COO Diego Fernandez Managing Director Main Street Capital Corporation NYSE: MAIN MAINST CAPITAL CORPORATION mainstcapital.com#45Headquarters Stevens Point, Wisconsin GAMBER JOHNSON Business Manufacturer of ruggedized docks and mounting systems for electronics Website www.gamberjohnson.com Original Investment Date June 2016 Main Street's View of Transaction and Background Investment Type First lien, senior secured term loan Majority equity investment Transaction Type Management Buyout / Leveraged Buyout ■ Original Capital Invested (1) -$25.0 million senior debt -$15.2 million equity ■ Additional Capital Invested (1) -$57.8 million senior debt -$3.5 million equity (1) MAIN (80%)/MSC Income Fund (20%) Main Street Capital Corporation ■ Gamber-Johnson Overview Founded in 1954, Gamber-Johnson ("Gamber", or the "Company") is a leading supplier of rugged mounting systems that safely secure mobile communication systems, computers, and other electronic equipment in fleet vehicles, public safety vehicles, forklifts, and other mobility applications ■ ■ ■ MAIN ST ■ CAPITAL CORPORATION Robust Platform for Strategic Acquisitions Since Main Street's investment in June 2016, Gamber-Johnson has completed five acquisitions, resulting in product diversification, end-market expansion, and vertical integration The Company's products are used by law enforcement, public safety, military, and warehouse fleets around the globe and are known for being rugged, reliable, and responsive Gamber-Johnson was owned by Leggett & Platt as an independently-operated subsidiary that was non- core to the corporate strategy leaving the management team with minimal capex and operating flexibility Acquisitions include Zirkona (December 2016), Precision Mounting Technologies ("PMT") (January 2017), Premier Mounts (March 2021), InfoCase (August 2022), and Lind Electronics ("Lind") (November 2022) 100% of the capital required to fund the 5 acquisitions came from Main Street, the management team, and internally generated cash flows Established and Enduring Partnerships with Blue-Chip OEMs Highly diversified customer base consisting of blue-chip computer and tablet OEMs/distributors with relationships of 15+ years Blue-chip original equipment manufacturers ("OEMs") include Panasonic, Dell, Samsung, Getac, Volvo, and Zebra, among others NYSE: MAIN Exclusive Access and Rigorous Standards within Industry High barrier to entry due to valuable Intellectual Property and stringent OEM certifications (ISO certified) Gamber-Johnson is one of the two prominent industry leaders showcasing well-established sales channels and widely recognized brand identity mainstcapital.com#46Business Overview | Gamber-Johnson Consolidated Company Overview Gamber-Johnson, founded in 1954, is a globally recognized supplier of rugged mounting systems for mobile communication systems and electronic equipment in various vehicles and mobility applications, trusted by law enforcement, public safety, military, and warehouse fleets worldwide for their durability and reliability ■ ■ ■ The Company offers a broad range of products and prides itself on the following core competencies - Safety & Stability, Customer Service, Product Reliability, Ergonomics & Functionality, and Innovation & Engineering Gamber-Johnson is one of only two OEM certified manufacturers of rugged docking solutions in the U.S. and Canada; the Company's products are primarily sold through its OEM partnerships and reseller distribution network The Company utilizes six sigma, 5S, and other lean manufacturing techniques to achieve streamlined processes End-Market Exposure OUBLIC SAFET POLICE HANDLING MATERIAL ENTERPRISE LOGISTICS G PRO AV MOUNT UP. Ри PREMBER RECREATIONAL outdoors zirkond GOMETN Docking Stations AMPANY Product Examples Material Handling Mounts SAMSUNG Blue-Chip Partners Panasonic DELL VOLVO St GAMBER JOHNSON Vehicle Mounts Power Adapters Getac ZEBRA#47Business Overview | Zirkona (Acquired in 2016) MAX MAX3 ■ Umea, Sweden Gamber-Johnson acquired Zirkona in December 2016 for its IP and unique ball-in-joint products ■ ■ GAMBER JOHNSON ■ zirkona > zirkona Zirkona produces flexible mounting systems, which supplement Gamber-Johnson's tablet docks, providing a less-bulky mounting alternative for light-weight electronics Zirkona manufactures the aluminum MAX3 product line Products are utilized for vehicles, homes, buses, helicopters, and other applications#48Business Overview | PMT (Acquired in 2017) = = = = ************* PMT PRESENTS R ■ Calgary, Canada Gamber-Johnson acquired Precision Mounting Technologies ("PMT") in January 2017 The acquisition expanded the Company's market reach & presence in Canada and acquired key customer relationships ■ I GAMBER JOHNSON ■ PMT > PMT PMT manufactures aluminum consoles and docking stations Products are smaller and have a lighter design, allowing for more space in a vehicle PMT's products are manufactured in-house#49Business Overview | Premier Mounts (Acquired in 2021) ■ I Corona, California Gamber-Johnson acquired Premier Mounts in March 2021 Premier Mounts has a portfolio of over 800 mounting solutions such as flat-panel display mounts, projector mounts, direct view LED mounts, carts, stands, adapters, and other accessories Typical end markets include hospitality, restaurant, retail, government, K-12, trade shows, and corporate Manufacturing has transitioned from in-house to outsourced by existing Gamber-Johnson vendors in the greater Wisconsin region ■ PREMIER MOUNTS ■ GAMBER JOHNSON PREMIER MOUNTS#50Business Overview | InfoCase (Acquired in 2022) DALL Getac ■ ■ InfoCase Cincinnati, Ohio Gamber-Johnson acquired InfoCase in August 2022 InfoCase's portfolio consists of protective cases, holsters, and other accessories for mobile devices InfoCase's top selling products include durable, snap-on polycarbonate laptop and tablet cases used in the education market InfoCase has relationships with OEM technology manufacturers, resellers, and distributors with key relationships including Panasonic, Synnex, Lenovo, Acer, Zebra, CDW, and Verizon ■ GAMBER JOHNSON InfoCase#51Business Overview | Lind Electronics (Acquired in 2022) LIND LIND ■ Minnetonka, Minnesota Gamber-Johnson acquired Lind Electronics ("Lind") in November 2022 Lind is a designer and supplier of rugged mobile power solutions Product lines include standard and custom AC/DC and DC/DC power adapters, battery chargers, dual USB adapters, shut down timers, solar charges, and stock & custom cables ■ GAMBER JOHNSON ■ LIND > LIND Lind is the only power adapter supplier in the market that is authorized and certified by OEM computer manufacturers Lind shares many of the same customers and end- markets as Gamber-Johnson#52Product Overview F Tablet Dock Material Handling WIERCE ***** Protective Cases Motion Attachment Base Power Adapters Console Box **** Pole Rugged Keyboard father Laptop Dock RELEAST QANDA H hee Ball & Joint Products Mounting Brackets GAMBER JOHNSON Keyboard Mount Display Mounts Printer Mount#53New Facilities Overview CGJ M S GAMBER JOHNSON 5001 JOERNS DR New World Headquarters in Stevens Point, Wisconsin LINENSOR PMT 515 58 Ave SE St New PMT Facility in Calgary, Canada The construction of new facilities has enhanced operational capabilities and streamlined processes to efficiently and effectively meet growing demand GAMBER JOHNSON#54Company Timeline Getac Start of Getac OEM partnership Gamber founded in Stevens Point, WI 1954 1999 Start of Panasonic OEM 2006 2007 partnership Panasonic Launch of international sales efforts in UK, UAE, Brazil Acquired by L&P Leggett & & Platt INCORPORATED MAIN ST CAPITAL CORPORATION Main Street acquires Gamber-Johnson in Jun 2016 2014 2015 2016 Start of Zebra OEM partnership for forklift applications ZEBRA DELL Initiation of OEM relationship with Dell President's "E" Star Award for Exports 2017 2018 Gamber acquires PMT in Jan 2017 PMT Gamber acquires Zirkona in Dec 2016 zirkona SAMSUNG Start of relationship with Samsung 2019 2020 Gamber completes construction of new HQ in Stevens Point, WI 2021 Wisconsin Manufacturer of the Year Grand Award St InfoCase Gamber acquires InfoCase in Aug 2022 GAMBER JOHNSON 2022 2023 Gamber acquires Lind in Nov 2022 LIND Gamber acquires Premier Mounts in Mar 2021 PREMIER MOUNTS#55Historical Financials | Revenue Growth MAIN ST CAPITAL CORPORATION Main Street acquires Gamber-Johnson in June 2016 zirkona 100% 2016 PMT 134% 2017 172% 2018 Revenue grew by ~3x in 6 years 186% 2019 Note: Historical periods are not pro forma adjusted for acquisitions 174% 2020 PREMIER MOUNTS 201% 2021 LIND InfoCase 233% 2022 | I I I 1 i T I I 1 | T I 1 1 ī T T 1 I I 1 I I I T I | I T I I T GAMBER JOHNSON 334% PF 2022 I 1 1 1 J I J 1 J 1 1 J I I J 1 I 1 J 1 1 I I#56Strategic Plan and Growth Initiatives Near-Term Deleverage Successfully Integrate Recent Acquisitions New Product Development to Drive Customer Acquisition Continue Being a Destination Employer and Grow Team Mid-Term Continue Acquisition Strategy Develop Electric Vehicle Market i Strategy Drive efficiencies and increase Gross Margin across various divisions Drive Revenue Growth via Cross-selling and R&D into New Markets I Long-Term GAMBER JOHNSON Continue Acquisition Strategy Explore Capital Market Opportunities Focus on International and End- Market Diversification Establish Long-term Management Transition Plan I#57(Equity Cost and FV $ in millions) GAMBER JOHNSON $60.0 $55.0 $50.0 $45.0 $40.0 $35.0 $30.0 $25.0 $20.0 $15.0 $10.0 $5.0 $0.0 $12.1 $12.1 $18.9 $14.8 *** $23.4 (A) 个 A-June 2016 Main Street and Gamber- Johnson's management team complete buy out of previous owner Main Street Capital Corporation ++++ $14.8 Transaction Dec-16 Dec-17 Date (B) 个 (C) 个 $45.5 $14.8 Historical Timeline and Valuations The Dec-18 $53.4 10 B - December 2016 Gamber-Johnson acquires Zirkona in December 2016 193 $14.8 .. ..…... ***.**. ***** ....... ** .......... ****** ******** ......... w ******** ********* ......... ******** **** ********** ........... ******** *** ******** ********** *** ... I $52.5 HES.. ora $14.8 ........ // ***.... ww wo Equity Cost ($) Adj. TTM EBITDA Growth % (from Transaction Date) Net Debt to Adj. TTM EBITDA as a % Dec-19 Dec-20 ******* $55.3 $17.7 www. wy + S to A ********* of t ..... ******* memor vorwe www. Mar-21 ********** outlet ........ ****** (D) ↑ C - January 2017 Gamber-Johnson acquires PMT in January 2017 $56.3 $17.7 ******... ******** m *** ...... for in www. 30 ********* ********* ****** ***** 247 ********* $55.4 An ******* NYSE: MAIN www. and A $17.7 www. M *****... ******* * 2 www. ******** ....... *** mune ******** ******** 2222 ***** ******* .….…... ****** $49.7 2722 J ****** xxx. *xxx D $17.7 ****** **** www D - March 2021 Gamber-Johnson acquires Premier Mounts in March 2021. ************* ********* ********* **** Jun-21 Sep-21 Dec-21 ........ ****** ******* ******** ******** ............ *** ******** ******** ****** ****** $45.1 2 W twit ********* D se no $17.7 ******** PUPIL ***** * www.Equity Fair Value ($) $46.3 ... 1723 $17.7 ******** ****** SIP AN $46,5 $17.7 (E) ↑ E - August 2022 Gamber-Johnson acquires InfoCase in August 2022 ******* 210 wit.. - ****** . 088 ........ til Berl www. ********* MAINST CAPITAL CORPORATION $50.9 $17.7 ******* Adj. TTM EBITDA Growth % (from Lind Acquisition Date) $59.4 $17.7 ******** ******** mere or ******* ******** ******** Aw **..... ...... ********** 00 Med Mar-22 Jun-22 Sep-22 Dec-22 Mar-23 22 ******** ........ 400% 375% 350% mainstcapital.com 325% 300% 275% 250% 225% 200% 175% 150% 125% 100% 75% 50% 25% 0% (F) ↑ F - November 2022 Gamber-Johnson acquires Lind Electronics in November 2022#58Main Street Capital Corporation MAINST CAPITAL CORPORATION Capital Structure June 2023 NYSE: MAIN mainstcapital.com#59(In millions) Our Capital Structure (¹) $4,900.0 $4,550.0 $4,200.0 $3,850.0 $3,500.0 $3,150.0 $2,800.0 $2,450.0 Long Term Capital $2,100.0 $1,750.0 $1,400.0 $1,050.0 $700.0 Moderate Term $350.0 Permanent Capital $- ■Equity SBIC Unfunded Capacity. 3-Year Notes (5) Credit Facilities Unfunded Capacity As of March 31, 2023 SBIC Debentures. ■5-Year Notes (5) Credit Facilities Funded) 100% MAIN maintains a conservative capital structure 90% 80% 70% 60% 50% 40% 30% 10% ● 0% ● ● Maximize access to beneficial Small Business Investment Company (SBIC) Debentures Equity and SBIC debentures represent over 50% of our capital Staggered debt maturities provide additional flexibility Opportunistically add additional long-term debt financing options utilizing Investment Grade ratings (BBB-/Stable) Maintain significant revolving credit facilities to provide liquidity between long-term debt and equity financings Maintain significant liquidity and flexibility Match capital structure with investment assets ● ● ● ● ● ● 20% Use conservative leverage to enhance shareholder returns Total Debt to Net Asset Value (NAV) of 0.92x(2) ● MAIN ST ● CAPITAL CORPORATION Utilize equity offerings to provide permanent capital to match long- term to indefinite holding periods for LMM investments and to maintain target leverage profile Duration Fixed vs Floating Non-SBIC Debt to NAV (regulatory leverage) of 0.77x(²) Weighted average yield (3) on existing debt investment portfolio of 12.5% vs weighted average cost of debt(4) capital of 4.9% (1) (2) SBIC Debentures are not included as "senior debt" for purposes of the BDC asset coverage requirements pursuant to exemptive relief received by MAIN; Debt to NAV Ratio is calculated based upon the par value of debt (3) Weighted-average effective yield is calculated using the applicable interest rate as of March 31, 2023 and includes amortization of deferred debt origination fees and accretion of original issue discount, but excludes fees payable upon repayment of the debt instruments and any debt investments on non-accrual status (4) Weighted Average Cost of Debt calculated utilizing stated interest rate of debt capital as of March 31, 2023 and includes amortization of deferred financing costs (5) Includes MAIN's corporate revolving credit facility (the Corporate Facility) and SPV credit facility (the SPV Facility and together, the Credit Facilities) Main Street Capital Corporation NYSE: MAIN mainstcapital.com#60● MAINST Expanded and Diversified Lending Relationships While Expanding Liquidity ● CAPITAL CORPORATION Maintained investment grade debt ratings by S&P Global Ratings and Fitch Ratings - S&P reaffirmed BBB-/Stable - Fitch Ratings assigned initial BBB-/Stable rating in July 2022 and reaffirmed in April 2023 Issued new or expanded existing debt financing and commitments, including support of existing and new lender relationships, totaling $530 million: - Increased total commitments on our Corporate Facility by $125.0 million to $980.0 million Entered into a new SPV Facility which includes $255.0 million in capacity due November 2027 - Issued $150.0 million of Series A/B unsecured notes due in December 2025 Repaid $185.0 million in unsecured notes which matured in December 2022 Raised net proceeds of $242.8 million (1) through equity offerings including $187.7 million through ATM equity offerings at an average issue price premium to NAV per share of approximately 50% and $55.1 million through an equity offering in August 2022 Expanded liquidity by $175.8 million to $710.8 million as of March 31, 2023 (²) (1) Includes ATM Equity offerings from March 31, 2022 through March 31, 2023 (2) Liquidity includes cash and cash equivalents and availability under Credit Facilities; expanded liquidity position measured from March 31, 2022 to March 31, 2023 Main Street Capital Corporation NYSE: MAIN mainstcapital.com#61BDC Industry Leverage Ratio Comparisons (1) MAIN's capital structure and leverage levels compare very favorably to other BDCS MAIN's capital structure benefits from a healthy mix of secured revolving debt (28% of total debt obligations (3)), unsecured Investment Grade debt (55% of its total debt obligations (3)) and attractive SBIC debentures (17% of total debt obligations (3)) MAIN's attractive Small Business Investment Company (SBIC) debentures provide favorable leverage SBIC debentures are viewed as "equity like" in structure • Regulatory leverage ratio of 0.77 (2) Long-term target leverage levels. continue to compare favorably to other BDCs MAIN Total Regulatory (2) Internally Managed BDCS High Low Median Debt to Book Equity Externally Managed BDCs All High Low Median 0.92 0.77 NYSE: MAIN 1.29 0.63 1.10 2.19 0.64 1.24 $100-$300 Market Capitalization High Low 2.19 0.82 Median 1.54 MAINST CAPITAL CORPORATION > $300 Market Capitalization High Low Median 1.51 0.64 1.23 <$100 Market Capitalization High Low Median 1.64 1.23 1.39 (1) Sourced from Raymond James BDC Weekly Market Update as of May 5, 2023 (2) As of March 31, 2023; Regulatory leverage ratio excludes SBIC debentures due to unique nature of these debentures and pursuant to exemptive relief MAIN received from the Securities and Exchange Commission (3) As of March 31, 2023 Main Street Capital Corporation mainstcapital.com#62MAIN ST CAPITAL CORPORATION MAIN's Target Leverage In May 2022, MAIN received Board and Stockholder approval to reduce its minimum regulatory asset coverage ratio (¹) from 200% to 150%; Our primary goal in obtaining the reduced minimum regulatory asset coverage ratio (1) is to provide us greater operational flexibility during times of significant macro disruptions An additional benefit is to provide MAIN with the flexibility to grow our investment portfolio under periods of robust net originations, when market conditions may not allow us to raise additional equity capital at a pace which keeps up with our investment activity MAIN's long-term leverage targets include a regulatory asset coverage ratio (¹) between 2.25x to 2.1x and a regulatory debt to NAV ratio (¹) between 0.8x to 0.9x Currently operating at a more conservative position outside of those ranges due to the current economic backdrop and market volatility P MAIN's leverage position could flex to a regulatory asset coverage ratio(¹) of ~ 2.0x and a regulatory debt to NAV ratio (¹1) of ~ 1.0x on a temporary basis under certain conditions (such as periods of robust originations coupled with lower than expected repayments and/or lower ATM equity issuance) In such an event, MAIN will accelerate equity issuances in the current and future quarters based upon such investment activities to adjust its leverage position back to its long-term targets NYSE: MAIN (1) SBIC Debentures are not included as "senior debt" for purposes of the BDC asset coverage requirements pursuant to exemptive relief received by MAIN; Debt calculated based on par value of debt Main Street Capital Corporation mainstcapital.com#63Stress Test 2023 Leverage Position Adjusted to the High End Target Leverage 4,609,255 ($'s in 000's) Total Assets Debt Capital Revolving Credit Facility SBIC Debentures Notes Payable Total Debt Total Debt, excl. SBIC Debentures Net Asset Value (NAV) As of March 31, 2023 $ 4,293,255 $ 564,000 $ 334,000 $ $ 1,100,000 $ 1,998,000 $ $ 1,664,000 $ 2,172,922 New Investments funded by Debt 316,000 $ 2.30 0.77 $ 300,000 $ 864,000 16,000 $ 350,000 $ 1,100,000 316,000 $ 2,314,000 $ $ 1,964,000 2,172,922 2.10 Stress Test (10% reduction in Fair Value $ (460,926) $ 0.90 $ $ Proforma after Stress Impacts $ $ $ $ (460,926) $ 4,148,330 NYSE: MAIN 1,964,000 1.87 MAINST CAPITAL CORPORATION 1.15 Additional Equity Issuances 864,000 $ (105,000) $ 350,000 $ 1,100,000 $ 2,314,000 $ (105,000) $ $ 1,711,997 $ 105,000 $ Proforma after Additional Equity Issuances $ 4,148,330 759,000 350,000 1,100,000 2,209,000 Asset Coverage Ratio Debt to Equity Ratio With the high-end target Asset Coverage Ratio of -2.1x and Debt to Equity Ratio of ~0.9x, a 10% reduction in investment fair values would result in an Asset Coverage Ratio of ~1.87x and a Debt to Equity Ratio of ~1.15x 1,859,000 1,816,997 The analysis above assumes no additional equity is raised - an action that MAIN would implement when market conditions allowed to enhance its leverage position (consistent with MAIN's actions in 2020 and 2021 in response to the impacts of the COVID-19 Pandemic) 1.97 1.02 A -$105 million equity issuance in the same scenario would enhance the Asset Coverage Ratio to -1.97x and the Debt to Equity Ratio to -1.02x Note: Asset Coverage Ratio means regulatory asset coverage ratio and Debt to Equity Ratio means regulatory debt to equity ratio; SBIC Debentures are not included as "senior debt" for purposes of the BDC asset coverage requirements pursuant to exemptive relief received by MAIN; Debt calculated based on par value of debt Main Street Capital Corporation mainstcapital.com#64Conservative Leverage = As of March 31, 2023 ($ in 000's) Total Assets Debt Capital: Credit Facilities (1) SBIC Debentures Notes Payable (2) Total Debt Net Asset Value (NAV) $ $ Non-SBIC 3,624,263 $ 564,000 1,097,435 1,661,435 $ 1,839,711 $ 4.05x 2.18x N/A 0.46x N/A SBICS 668,992 328,206 NYSE: MAIN 328,206 $ 333,211 $ MAINST T 6.19x 2.00x N/A 0.49x N/A CAPITAL CORPORATIONON Key Leverage Stats Interest Coverage Ratio (3)(8) 4.33x 2.15x Asset Coverage Ratio (4) Consolidated Asset Coverage Ratio - Regulatory(5) 2.30x Debt to Assets Ratio 0.46x Regulatory Debt to NAV Ratio (5) (6) 0.77x Debt to NAV Ratio (6) 0.90x 1.00x 0.92x Net Debt to NAV Ratio (7) 0.89x 0.98x 0.90x (1) As of March 31, 2023, MAIN maintained the Corporate Facility and the SPV credit facility, which had $980.0 million and $255.0 million in total commitments with accordion features with the right to request increases up to $1.4 billion and $450.0 million, revolving periods until August 2026 and November 2025 with maturity dates in August 2027 and November 2027, respectively (2) Includes the carry value of the July 2026 Notes ($498.3 million; $500.0 million par), the May 2024 Notes ($450.6 million; $450.0 million par) and the December 2025 Notes ($148.6 million; $150.0 million par) Total 4,293,255 564,000 328,206 1,097,435 1,989,641 2,172,922 (3) Distributable Net Investment Income (DNII) + interest expense / interest expense on a trailing twelve-month basis (4) Calculated as total assets divided by total debt at par, including SBIC Debentures ($334.0 million), July 2026 Notes ($500.0 million), May 2024 Notes ($450.0 million) and December 2025 Notes ($150.0 million) (5) Calculated per BDC regulations; SBIC Debentures are not included as "senior debt" for purposes of the BDC asset coverage requirements pursuant to exemptive relief received by MAIN (6) Debt to NAV Ratio is calculated based upon the par value of debt (7) Net debt in this ratio includes par value of debt less cash and cash equivalents of $33.3 million, $6.5 million and $39.8 million for the Non-SBIC, SBICs and Total, respectively (8) See Main Street Investor Presentation, available on the MAIN website, for the reconciliation of Distributable Net Investment Income (DNII) to Net Investment Income (page 38) and for Non-GAAP information disclosures and discussion of DNII (page 48) Main Street Capital Corporation mainstcapital.com#65MAIN's Historical Asset Coverage Ratio: Consolidated Asset Coverage Ratio - Regulatory(1) Prior Minimum Required Asset Coverage (2) Cushion % above Prior Minimum Required Asset Coverage Current Minimum Required Asset Coverage (2) Cushion % above Current Minimum Required Asset Coverage Conservative Leverage Regulatory Passage of the Small Business Credit Availability Act in December 2017 provided the opportunity for BDCs to obtain board or shareholder approval to access additional leverage by lowering the required asset coverage to 1.50x MAIN received shareholder approval, effective as of May 3, 2022, to adopt the 1.50x asset coverage ratio MAIN has historically operated at conservative regulatory leverage levels, in all cases with significant cushion to the 1.50x regulatory limits, and proven through historical performance that MAIN does not require access to additional leverage to generate market leading returns 2018 3.22x 2.00x 61% 1.50x 115% 2019 2.89x 2.00x 45% 1.50x 93% 2020 2.67X 2.00x 34% 1.50x 78% 2021 2.22x 2.00x 11% 1.50x MAIN STI 48% CAPITAL CORPORATIONON 2022 2.27X N/A N/A 1.50x 51% Q1 2023 2.30x N/A N/A 1.50x 53% (1) Calculated per BDC regulations; SBIC Debentures are not included as "senior debt" for purposes of the Minimum Asset Coverage Ratio requirements pursuant to exemptive relief received by MAIN (2) MAIN received shareholder approval, effective as of May 3, 2022, to adopt the 1.5x asset coverage ratio (decreased from the previously required asset coverage ratio of 2.0x) Main Street Capital Corporation NYSE: MAIN mainstcapital.com#66Conservative Leverage - Excess Collateral Improves Over Time MAIN's conservative use of leverage and equity to fund its growth results in significant excess collateral that provides protection to lenders MAIN's management of its capital structure results in reduced risk profile for debt investors over time Excess collateral available to unsecured lenders has increased by 218% since MAIN's first investment grade (IG) debt issuance ($ millions) Total Assets Excluding SBIC Assets Add: Equity Value of SBIC Entities (2) Total Collateral Available to Secured Lenders Less: Secured Debt (Credit Facilities) Excess Collateral Available to Unsecured Lenders Increase since first IG debt issuance (3) Less: Unsecured Debt Outstanding (par value) Remaining Excess Collateral Available to Unsecured Lenders Increase since first IG debt issuance (³) 9/30/2014 (1) 3/31/2023 $ $ $ 1,137 $ 218 1,355 (287) 1,068 MAIN STI CAPITAL CORPORATIONON (91) 977 (3) First IG notes issued in November 2014 (4) Includes additional IG debt issuances in April 2019, December 2019, July 2020, January 2021, October 2021, December 2022 and February 2023 Main Street Capital Corporation NYSE: MAIN 3,624 333 $ 3,957 $ (564) 3,393 218 % (1,100) $ 2,293 135 % (4) (1) Most recent information publicly reported prior to first IG debt issuance (2) Represents asset value in excess of SBIC debt (par value); SBIC assets contain negative pledge in relation to SBIC debt; therefore, equity at SBIC entities is effectively collateral for lenders mainstcapital.com#67MAIN maintains a conservative capital structure, with limited overall leverage and an intentional mix of secured, floating rate revolving debt and unsecured, fixed rate long-term debt Stable, Long-Term Leverage - Significant Unused Capacity Capital structure is designed to correlate to and complement the expected duration and fixed/floating rate nature of investment portfolio assets Facility $980.0 million Corporate Facility (1)(3) $255.0 million SPV Facility (2) (3) Notes Payable Notes Payable Notes Payable SBIC Debentures Interest Rate SOFR+1.875% floating (6.6% (4)) SOFR+2.50% floating (7.3% (4)) 3.00% fixed 5.20% fixed 7.74% (5) fixed (weighted average) 2.87% fixed (weighted average) Maturity August 2027(1) MAINST T November 2027 (2) CAPITAL CORPORATIONON Redeemable at MAIN's option at any time, subject to certain make whole provisions; Matures July 14, 2026 Redeemable at MAIN's option at any time, subject to certain make whole provisions; Matures May 1, 2024 Redeemable at MAIN's option at any time, subject to certain make whole provisions; Matures December 23, 2025 Various dates between 2023 - 2031 (weighted average duration = 5.1 years) Principal Drawn $394.0 million $170.0 million $500.0 million $450.0 million $150.0 million $334.0 million (1) As of March 31, 2023, MAIN maintained a corporate revolving line of credit (the Corporate Facility), which had $980.0 million in total commitments with an accordion feature with the right to request an increase up to $1.4 billion; the Corporate Facility is fully revolving until August 2026, with a maturity date in August 2027 (2) As of March 31, 2023, MAIN maintained a secured special purpose vehicle financing facility (the SPV Facility), which had $255.0 million in total commitments with an accordion feature with the right to request an increase up to $450.0 million; the SPV Facility is fully revolving until November 2025, with a maturity date in November 2027 (3) Borrowings under the Corporate Facility and the SPV Facility (together, the Credit Facilities) are available to provide additional liquidity for investment and operational activities (4) Credit Facilities' rates reflect the rate based on SOFR as of March 31, 2023 and effective as of the contractual reset date as of April 1, 2023 (5) Based upon $100.0 million and $50.0 million in aggregate principal amount bearing interest at 7.84% and 7.53%, respectively Main Street Capital Corporation NYSE: MAIN mainstcapital.com#68Long-term Maturity of Debt Obligations MAIN's conservative capital structure provides long-term access to attractively- priced and structured debt facilities Allows for investments in assets with long-term holding periods / illiquid positions and greater yields and overall returns Provides downside protection and liquidity through economic cycles Allows MAIN to be opportunistic during periods of economic uncertainty (in millions) $900 $850 $800 $750 $700 $650 $600 $550 $500 $450 $400 $350 $300 $250 $200 $150 $100 $50 $0 2023 $450.0 $63.8 2024 $150.0 2025 SBIC debentures December 2025 Notes (3) $500.0 2026 $564.0 $75.0 2027 Credit Facilities July 2026 Notes (4) $75.0 2028 2029 MAINST T CAPITAL CORPORATIONON May 2024 Notes (2) $35.0 2030 $85.2 2031 (1) As of March 31, 2023, MAIN maintained the Corporate Facility and the SPV Facility, which had $980.0 million and $255.0 million in total commitments with accordion features with the right to request increases up to $1.4 billion and $450.0 million, revolving periods until August 2026 and November 2025 with maturity dates in August 2027 and November 2027, respectively (2) Issued in April 2019; with follow-on issuances in December 2019 and July 2020; redeemable at MAIN's option at any time, subject to certain make-whole provisions (3) Issued in December 2022; with a follow-on issuance in February 2023; redeemable at MAIN's option at any time, subject to certain make-whole provisions (4) Issued in January 2021; with a follow-on issuance in October 2021; redeemable at MAIN's option at any time, subject to certain make-whole provisions Main Street Capital Corporation NYSE: MAIN mainstcapital.com#69Match Funding with Investment Assets (1) MAIN maintains a capital structure that is designed to match our capital funding with our investment assets The term of our capital sources is matched with the expected hold period of our portfolio investments (% of total) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Long-term / Moderate-term Capital H Permanent Capital MAIN'S Capital Investments at FMV Moderate-term / partially illiquid Investments Long-term / illiquid Investments MAIN ST ■MAIN Equity SBIC Debentures 5-Year Notes 3-Year Notes ■Credit Facilities (2) (1) As of March 31, 2023; Investment Assets exclude investments in our Other Portfolio, Short-term Portfolio and MSC Adviser I, LLC (2) Outstanding funded balance only; excludes the unfunded capacity from MAIN's Credit Facilities Main Street Capital Corporation NYSE: MAIN CAPITAL CORPORATION Investments at Cost Equity Investments LMM Debt Investments PL Debt Investments MM Debt Investments mainstcapital.com#70At-The-Market (ATM) Equity Program ATM Equity Program provides efficient and low cost access to equity capital ● Provides access to equity capital to match growth of LMM investments on an as- needed basis Provides significant economic cost savings compared to traditional overnight equity offerings Provides permanent capital to match indefinite or long-term holding period for LMM investments Facilitates maintenance of conservative leverage position Issued equity is accretive to NAV per share Provides significant benefits vs traditional overnight equity offerings ● MAIN STI CAPITAL CORPORATIONON • Provides equity capital at significantly lower cost ● Avoids negative impact to stock price from larger overnight equity offerings ● ● Provides equity capital and liquidity on an as-needed basis, avoiding dilution from larger overnight equity offerings Raised net proceeds of $869.7 million since inception in 2015 (1) Average sale price is approximately 62% above average NAV per share over same period (1) (1) Through March 31, 2023 (2) Assumes 6% all-in cost for traditional overnight equity offering Main Street Capital Corporation Resulted in economic cost savings of approximately $43.9 million when compared to traditional overnight equity offering (1)(2) NYSE: MAIN mainstcapital.com#71Retention of Future Realized Gains / Supplemental Dividends MAIN plans to retain future realized gains for reinvestment Main Street Capital Corporation ● Current plan is to retain capital from realized gains on our equity investments for future reinvestment purposes (as opposed to paying these realized gains out as supplemental dividends) as another tool to maintain conservative leverage ● MAIN ST ● CAPITAL CORPORATION We expect to recommend that our Board declare future Supplemental Dividends only to the extent Distributable Net Investment Income (DNII) significantly exceeds monthly dividends paid in future quarters Supplemental Dividends, if any, would be at a discount to actual excess earnings LMM portfolio continues to perform at a very high level, providing opportunity for additional realized gains in the future Any Supplement Dividends would also be in arrears on a quarterly basis, providing additional flexibility NYSE: MAIN In March 2023, MAIN declared its largest and seventh consecutive quarterly supplemental dividend to be paid in June 2023, with this supplemental dividend representing only 57% of the DNII in excess of the monthly dividend for the first quarter of 2023 mainstcapital.com#72Main Street Capital Corporation MAINST CAPITAL CORPORATION Lower Middle Market Strategy & Valuations June 2023 NYSE: MAIN mainstcapital.com#73Lower Middle Market (LMM) Investments Overview LMM Dynamics ■ ■ ■ Invest in generally underserved market of smaller companies with attractive risk-adjusted return profiles Large market with 195,000+ domestic businesses (1) Portfolio Composition ■ Self-sponsored investment thesis whereby MAIN partners with existing portfolio company management teams, owners and operators (1) Highly diverse portfolio: ■ Differentiated Strategy Generalist strategy to with no significant exposure to any specific industries or end markets Highly diversified with 79 companies, with no individual company representing more than 3.1% of MAIN's assets, or 3.7% of MAIN's income I "One-Stop-Shop" strategy of investing in both the debt and equity in LMM companies Equity investments provide upside, while debt investments protect the downside Public company vehicle allows for long-term to permeant hold positions, which our LMM partners value Investment Size Target Purchase Price Multiple Target Leverage MAIN Equity Ownership EBITDA Interest Rate Target Investment Profile $25 million $75 million Current average size of $26.7 million value ■ MAINST - 4.5x6.5x Enterprise Value / EBITDA CAPITAL CORPORATION - 2.0x 4.0x EBITDA at entry (2) Current average leverage of 3.1x I - Target of $3 million $20 million Current average of $8.3 million (2) 15% - 85% (2) Current average ownership position of 41% (2) (and 50% including MSC Income Fund) (2) at fair 10.0% - 14.0%; 12.0%+ at initial investment Current weighted average cash-coupon of (2) 12.4% (2) Existing portfolio as of March 31, 2023 (3) Includes companies which (a) MAIN is invested in direct equity and (b) are flow-through entities for tax purposes; based upon dividend income for TTM period ended March 31, 2023 Main Street Capital Corporation NYSE: MAIN Source: U.S. Census 2017 - U.S. Data Table by Enterprise Receipt Size; 2017 County Business Patterns and 2017 Economic Census; includes Number of Firms with Enterprise Receipt Size between $10,000,000 and $99,999,999 mainstcapital.com#74Lower Middle Market (LMM) Investments Overview (cont.) Investment Objectives ■ ■ ■ ■ ■ Achieve high relative cash yield from secured debt investments Debt Profile (2) (73% of MAIN's portfolio at cost) ■ Lower leverage profiles than available in larger credits Attractive equity investment valuation levels (1) Benefit from dividend income, unrealized appreciation and periodic capital gains as equity investments mature over tim e Equity Profile (2) Opportunity for cash dividend income, fair value appreciation and capital gains 99% of debt investments have first lien position Attractive yields averaging 12.6% Equity Ownership 100% of LMM portfolio companies 41% (2) average MAIN ownership (and 50% (2) combined for MAIN and MSC Income Fund) ■ (3) 64% of LMM companies with direct equity investment are currently paying dividends and 63% have fair value (2) appreciation Investment Size Target Purchase Price Multiple Target Leverage MAIN Equity Ownership EBITDA Interest Rate Target Investment Profile $25 million $75 million Current average size of $26.7 million value ■ MAINST - 4.5x6.5x Enterprise Value / EBITDA CAPITAL CORPORATION 2.0x 4.0x EBITDA at entry (2) Current average leverage of 3.1x - I Target of $3 million $20 million Current average of $8.3 million (2) - 15% - 85% (2) Current average ownership position of 41% (2) (and 50% including MSC Income Fund) (2) at fair 10.0% - 14.0%; 12.0%+ at initial investment Current weighted average cash-coupon of (2) 12.4% (2) Existing portfolio as of March 31, 2023 (3) Includes companies which (a) MAIN is invested in direct equity and (b) are flow-through entities for tax purposes; based upon dividend income for TTM period ended March 31, 2023 Main Street Capital Corporation NYSE: MAIN Source: U.S. Census 2017 - U.S. Data Table by Enterprise Receipt Size; 2017 County Business Patterns and 2017 Economic Census; includes Number of Firms with Enterprise Receipt Size between $10,000,000 and $99,999,999 mainstcapital.com#75LMM Transaction Type and Composition (1) MAIN'S LMM investments primarily support recapitalization, buyout management ("MBO") and, to a lesser extent, leveraged buyout ("LBO") transactions Investments are comprised of 1st lien debt and have meaningful equity investments, which aligns us with our portfolio company management team partners Invested Capital by Transaction Type LBO/MBO Acquisition Growth Capital 27% 6% 3% (1) Existing portfolio as of March 31, 2023 Main Street Capital Corporation 64% Recapitalization /Refinancing Security Position on Debt Capital as a % of Cost 1st Lien NYSE: MAIN 25.0% - 49.9% 99% 38% 1% MAIN ST CAPITAL CORPORATION Fully Diluted Equity Ownership % 29% 2nd Lien/Other 33% 1.0% - 24.9% 50% and greater mainstcapital.com#76Strong Industry Diversity in Current LMM Portfolio (1) (2) Our LMM portfolio of 79 investments industry represents attractive diversity Industry Diversification MAIN seeks significant industry. diversification as a portfolio risk mitigant Investing in Industrials Industrials represent a significant portion of the U.S. economy, including in the LMM; companies in this industry fit well with MAIN's long-term investment strategy Minimizing Energy Exposure Only 5% of the portfolio remains exposed to energy, and no new platform investments have been made in the energy industry since 2015 ■ 2% 3% 3% 4% 5% 7% 9% 10% 13% 19% 25% 1% 1% 1% 12% 4% 7% 12% 0% 14% 4% 9% 16% 19% Current Main Portfolio (1) Broader LMM (2) (1) As of March 31, 2023 (2) Broader LMM sourced from Sutton Place Strategies; represents closed deals over the period 1/1/2015 - 3/31/2023 (with a size of $10MM to $249MM EV) Main Street Capital Corporation NYSE: MAIN MAIN ST CAPITAL CORPORATION ■Telecommunication (0% / 1%) Transportation (0% / 1%) Financials (0% / 12%) Media (2% / 4%) Other (3% / 0%) Energy (3% / 7%) Health Care (4% / 12%) Hotels, Restaurants & Leisure (5% / 0%) Business Services (7% / 14%) Retail (9% / 1%) Food/Beverage (10% / 4%) Consumer Products/Services (13% / 9%) Technology (19% / 16%) Industrials (MAIN 25% / SPS 19%) mainstcapital.com#77LMM Portfolio by Vintage MAIN'S LMM has a well seasoned LMM portfolio (1): I ■ ■ Over time, our LMM portfolio companies typically deleverage with free cash flow from operations, which provides opportunities to: Make dividends/distributions ■ 46 LMM portfolio companies (58% (²) of LMM portfolio) invested for over 5 years ■ 19 LMM portfolio companies (24% (2) of LMM portfolio) invested for over 10 years Re-invest in growth strategies; organic or through acquisitions Buyout aging equity partners (potentially increasing our equity ownership) $ in millions $ in millions $350 $300 $250 $200 $150 $100 $50 $0 $1,000 $900 $800 $700 $600 $500 $400 $300 $200 $100 $0 8 Cumulative Investments by Investment Date (1)(3) > 5-6 yrs 19 10 9 I I > 6-8 yrs FV $ > 10 yrs 28 > 8 yrs > 8-10 yrs FV% Cumulative Investments by Investment Date (1)(3) 46 FV $ 39 MAIN ST > 6 yrs CAPITAL CORPORATION FV % 19 > 10 yrs > 5 yrs 16% 14% 12% 10% 8% 6% 4% 2% 0% 50% 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% % of Total LMM Investments at FV mainstcapital.com % of Total LMM Investments at FV (1) Aging as of June 19, 2023; fair value as of March 31, 2023; based upon original investment date in each portfolio company and including the value of all investments in each portfolio company in any period (2) Based on number of LMM portfolio companies as of March 31, 2023 (3) Numbers at the top of bars for each year in charts represent the number of portfolio investments based on the date of MAIN's initial investment in each portfolio company Main Street Capital Corporation NYSE: MAIN#78$547.2 $78.6 LMM Equity Valuation (1) Opportunistic and selective posture toward new investment activity, combined with the benefits of long-term to permanent holding periods, creates a diversified portfolio of high quality, seasoned assets with attractive risk-adjusted return characteristics Equity component of LMM portfolio at fair value equals 191% of cost(1) As MAIN's LMM portfolio companies season, they typically de-leverage and experience equity appreciation $223.0 $231.6 2018 $ in millions $14.0 $594.6 $33.0 $246.6 (1) As of March 31, 2023 Main Street Capital Corporation $309.1 2019 Prior Vintages (Cost) Current Year Investments (Cost) $5.8 $609.1 $62.3 $218.2 $315.4 2020 $13.3 $745.0 $78.7 NYSE: MAIN $317.6 $345.1 2021 $3.5 Prior Vintages (Net Appreciation) Current Year Investments (Net Appreciation) MAIN ST CAPITAL CORPORATION $860.4 $35.4 $408.2 $416.8 2022 mainstcapital.com#79■ Aggregate LMM Dividend Income Over Time As a result of our LMM equity strategy, dividend income across the LMM portfolio has grown over time and has proven to be a growing stream of recurring income for MAIN $32.7 As our LMM portfolio grows, continues to season and deleverage, we anticipate dividend income to continue provide long term growth to MAIN's income 2018 $ in millions Main Street Capital Corporation $34.7 2019 15.6% CAGR $27.8 2020 NYSE: MAIN MAINST $64.2 CAPITAL CORPORATION 2021 $58.2 2022 mainstcapital.com#80■ Committed to Growing Our LMM Team (1) Since 2018, MAIN has grown its LMM headcount by nearly 50% in order to manage and grow its LMM investment portfolio ■ MAIN has actively added new LMM investment professionals to execute on LMM investment opportunities, including a mix of experienced and junior investment professionals 28 MAIN continues to build its talent pipeline by recruiting analysts straight out of college; we train our employees how to execute and manage LMM investments the "Main Street Way" 31 2019 31 2020 7.9% CAGR 32 2018 (1) Headcount excludes Business Development/Marketing and FP&A personnel focused on MAIN's LMM activities (2) June 2023 headcount includes new hires which have accepted employment offers and will join in June; CAGR calculated using June as an end of year estimate Main Street Capital Corporation NYSE: MAIN 2021 MAIN ST 36 CAPITAL CORPORATION 2022 41 2023 (2) mainstcapital.com#81Supporting LMM Growth Through Acquisitions As an equity owner, we are aligned with our LMM portfolio companies and our management team partners in their efforts to grow their businesses and achieve their strategic objectives, including (among others): ■ Geographic expansion, product/service expansion, cross-selling opportunities, purchasing power benefits, and operating synergies Follow-on investments have grown as a % of our LMM originations over time: LMM New Portfolio Company and Follow-on Investments (2) 7% 93% 2018 22% 78% 25% 75% 36% 64% 2019 2020 2021 ■New Platforms Add-Ons 58% 42% 2022 $384.6 $25.4 $359.2 2018 $120.6 $26.5 $94.1 $284.6 $71.0 $213.6 $653.3 $236.1 MAIN ST $417.2 CAPITAL CORPORATION 2019 2020 2021 New Platforms Add-ons $352.8 $204.9 $147.9 2022 $ in millions Since last year, MAIN has supported 9 LMM companies complete 14 acquisitions (¹), representing $178 million ($207 million including amounts allocated to managed funds (2)) (1) Represents activity from April 1, 2022 through March 31, 2023 (2) Includes investments by MAIN and MSC Income Fund, a fund managed by MSC Adviser I, LLC (the External Investment Manager), MAIN's wholly owned unconsolidated registered investment adviser subsidiary Main Street Capital Corporation NYSE: MAIN mainstcapital.com#82Follow-on Investment Case Studies Gamber-Johnson Company Description Leading supplier of rugged mounting systems that safely secure mobile communication systems, computers, and other electronic equipment in fleet vehicles, public safety vehicles, forklifts, and other mobility applications Initial Transaction Management buyout/corporate carve out Company's management team sought a financial partner that shared management's vision of investing in the future growth of the business Acquisition Strategy / Rationale Two-pronged acquisition strategy: Diversify end market exposure ■ Strengthen competitive position Completed five acquisitions providing exposure to new end markets, geographic regions, customers, and products ■ ■ PMT LIND - Representative Acquisitions Primary competitor of mobile mounting solutions in the Canadian market Provided additional manufacturing capabilities to produce bent metal products in-house ■ ■ $40.5 $15.5 $25.0 Initial Capital Invested and Subsequent Investments (¹) $ in millions $109.5 Designer and provider of ruggedized mobile power supply units Adjacent product portfolio to Gamber- Johnson's existing offering, allowing for increased wallet share with customers $69.0 million, or 170%, of Additional Invested Capital Initial Invested Capital MAIN ST (1) Includes the total debt and equity invested through March 31, 2023, including MAIN and funds managed by the External Investment Manager Main Street Capital Corporation NYSE: MAIN CAPITAL CORPORATION ■Debt Equity $22.1 $87.4 Total Invested Capital mainstcapital.com#83Follow-on Investment Case Studies GRT Company Description ■ Initial Transaction Manufacturer of engineered rubber products for a variety of end markets GRT manufactures rubber belting, wear and impact liners, sheet rubber products, screen media and other molded products ■ Acquisition Strategy / Rationale GRT management sought to: ■ Management buyout / corporate carve out Previously a "corporate orphan" whose management team sought a financial partner that would invest in the future growth of the business ■ Diversify end market exposure Diversify sales channels Vertically integrate Successfully completed two highly strategic acquisitions Valley RUBBER Gorilla Tough for Mining & Aggregato Biltrite Ripley Operations Representative Acquisitions ▪ Manufacturer of custom rubber solutions and molded products Provided additional manufacturing capabilities, end market exposure, sales channel diversification, and geographic diversification ■ Vertically integrated industrial sheet rubber and rubber products manufacturer ▪ Provided vertical integration through the addition of in-house rubber mixing capabilities. $44.5 Initial Capital Invested and Subsequent Investments (¹) $ in millions $19.5 $25.0 $47.3 million, or 106%, of Additional Invested Capital MAIN ST Initial Invested Capital CAPITAL CORPORATION (1) Includes the total debt and equity invested through March 31, 2023, including MAIN and funds managed by the External Investment Manager Main Street Capital Corporation NYSE: MAIN Debt Equity $91.8 $19.5 $72.3 Total Invested Capital mainstcapital.com#84Follow-on Investment Case Studies Hawk Ridge Company Description Initial Transaction ■ Value-added reseller of engineering, design and manufacturing software and additive manufacturing solutions (3D printing) Provides online training, engineering services and other value-added services as additional revenue streams sold alongside software programs and additive manufacturing solutions ■ Minority recapitalization that allowed the CEO to obtain a majority equity position and provided full liquidity to inactive equity owners CEO sought a financial partner with a long-term holding period and shared vision for future growth Acquisition Strategy / Rationale Multi-pronged acquisition strategy: Expand geographic footprint ■ ■ Drive revenue synergies by upselling into acquired customer bases Identify additional ways to monetize customer base through new service and product offerings Representative Acquisitions Completed ten acquisitions since MAIN's initial investment, including six significant acquisitions and four smaller "tuck in" acquisitions Significantly expanded the company's geographic coverage Materially changed and expanded the Company's service offerings and revenue sources $42.7 million, or 262%, of Additional Invested Capital MAIN ST Initial Capital Invested and Subsequent Investments (¹) $ in millions $16.3 $3.8 $12.5 Initial Invested Capital CAPITAL CORPORATION (1) Includes the total debt and equity invested through March 31, 2023, including MAIN and funds managed by the External Investment Manager Main Street Capital Corporation NYSE: MAIN ■Debt Equity $59.0 $3.8 $55.2 Total Invested Capital mainstcapital.com#85Follow-on Investment Case Studies Heritage Vet Partners Company Description Initial Transaction Leading provider of veterinary services and animal health products primarily for livestock producers throughout the Midwest U.S. ■ Company sought a financial partner that would assist with its strategic plan and growth initiatives and provide acquisition expertise Acquisition Strategy / Rationale Increased scale to improve buying power and cost saving benefits, strengthening margins and profitability Expand geographic reach Strengthen competitive position Completed nine acquisitions from December 2021 through June 2023 ■ Minority recapitalization with access to additional debt financing for future growth St. Anna Veterinary Clinic CORNERSTONE VETERINARY SERVICES $ in millions ■ Representative Acquisitions ▪ Traditional vet practice evenly split between product and service sales Immediately allowed for increased product sales to existing customers, improving cost of goods sold and profitability ▪ Products-focused practice with pre-existing distributor relationships Increased buying power with distributors, expanded product offering and expanded geographical coverage Initial Capital Invested and Subsequent Investments (¹) ■ $17.0 $6.5 $10.5 $20.6 million, or 121%, of Additional Invested Capital Initial Invested Capital (1) Includes the total debt and equity invested through March 31, 2023, including MAIN and funds managed by the External Investment Manager Main Street Capital Corporation NYSE: MAIN MAIN ST ■Debt CAPITAL CORPORATION Equity $37.6 $7.0 $30.6 Total Invested Capital mainstcapital.com#86Conservative Historical Nature of MAIN's Valuations for Equity Investments MAIN valuation approach and key inputs Market-comparable/historical cash flow approach ■ EBITDA Multiple ▪ Based on actual MAIN entry transaction multiples, as adjusted over time for overall market and specific company changes ▪ MAIN EBITDA valuation multiples compare favorably to industry and market valuations: MAIN Weighted Average (¹) MAIN Median (1) Other BDC's - All Equity (2) Industry (3) MAINST 6.8x 6.2x 10.1x CAPITAL CORPORATION 10.7x ▪ Discounted cash flow (DCF) approach Weighted average cost of capital (WACC) - significant component of DCF approach is significantly impacted by industry and overall market factors ▪ These WACC components are obtained from third party sources and can fluctuate significantly from quarter to quarter, thereby impacting MAIN's valuations (1) As of March 31, 2023 (2) As published in the most recent Form 10-K or Form 10-Q filed by each BDC as of May 19, 2023; Other BDCs includes 36 BDCs and includes weighted average EBITDA multiples for all forms of equity investments (3) Source: Lincoln International Valuations & Opinions Group Private Market Perspectives dated May 2023 as published by Lincoln International; multiples represent Total Enterprise Value / Adjusted EBITDA for the Last 12 Months as of March 31, 2023, for all transactions with less than $50 million in EBITDA Main Street Capital Corporation NYSE: MAIN mainstcapital.com#87MAIN LMM Strategy Produces Differentiated Returns to Investors Exits of LMM equity investments resulting in realized gains have compared. favorably to previously recorded fair values Realized Value at Exit in Comparison to Prior Qtr FV Realized Value at Exit in Excess of Prior Qtr FV ($ in million's) ▪ Exits of 51 LMM equity investments with realized gains have resulted in total realized gains of $291 million (¹) % of LMM companies with MAIN Equity Investment Two Quarters Prior to Exit 123% (1) For the period from initial public offering in 2007 through March 31, 2023 (2) As of March 31, 2023 Main Street Capital Corporation $75.9 With Unrealized Appreciation 63% Number of LMM companies with MAIN Equity 50 Investment Net Unrealized Appreciation of ~$4.82 per share, or $385 million, from LMM equity investments (2) Portfolio diversity has resulted in LMM equity investment appreciation across a diverse group of portfolio companies and industries NYSE: MAIN Four Quarters Prior to Exit 151% $136.4 MAIN ST With Unrealized Depreciation CAPITAL CORPORATION 25% 20 mainstcapital.com#88MAIN ST MAIN LMM Strategy Produces Differentiated Returns to Investors (1) CAPITAL CORPORATION Equity Exits Enhance MAIN's Portfolio Returns ▪ LMM equity exits have enhanced MAIN's portfolio returns and provided significant upside, in addition to offsetting the inevitable credit losses occurring from non-investment grade debt investments (1) For the period from initial public offering in 2007 through March 31, 2023 Main Street Capital Corporation ▪ LMM equity exits have achieved the following long-term benefits for Main Street and continue to help us achieve superior returns for our investors when compared to other BDC's ▪ Exits of 51 LMM equity investments resulted in total realized gains of $291 million. ▪ Exits of 28 LMM equity investments resulted in total realized losses of $59 million ▪ Net realized losses on exits and restructurings of LMM debt investments of $113 million ▪ Cumulative net realized gains across all LMM investments of $119 million NYSE: MAIN mainstcapital.com#89Main Street Capital Corporation ELGIT Bill Skok President and Chief Executive Officer Jesse Morris Executive Vice President, Chief Financial Officer and Chief Operating Officer Main Street Capital Corporation NYSE: MAIN MAIN ST CAPITAL CORPORATION mainstcapital.com#90ELGIN Headquarters Elgin, Illinois Business Third generation, family owned and managed, fully integrated supplier of engine and chassis components to OEMS and Aftermarket Website https://www.elginind.com Original Investment Date October 2022 Investment Type First lien, senior secured term loan Majority equity investment Transaction Type Majority Recapitalization Original Capital Invested $20.0 million Term Loan (¹) $6.1 million Equity (1) (1) MAIN 94% / MSC Income Fund 6% Main Street's View of Transaction and Background Main Street Capital Corporation ■ Elgin Industries Overview Founded in 1919, Elgin Industries, Inc. ("Elgin" or the "Company") is a Tier One fully-integrated manufacturer and distributor of engine and chassis components to a diverse group of global original equipment manufacturers ("OEMS") across the automotive, commercial vehicle, powersport, and industrial equipment markets. Elgin also offers an extensive range of replacement components and kits to ftermarket customers ("Aftermarket") worldwide ■ ■ ■ ■ Strong Market Position and Reputation Elgin is the dominant supplier of its four manufactured products to the OEM and Aftermarket segments Maintains Tier One status with marquee OEMs, has achieved the highest level of quality certificate from its largest customer and has earned dozens of quality awards ■ MAIN ST ■ CAPITAL CORPORATION In October 2022, Main Street ("MAIN") partnered with the Company's existing owners and management team to facilitate the transaction and provide growth capital, with Main Street and its co-investor funding $26.1 million in a combination of first-lien, senior secured term debt and a direct equity investment Main Street and its co-investor also provided Elgin with a revolving line of credit to support the Company's future growth initiatives and working capital needs - Significant Growth Opportunities Favorable tailwinds in Aftermarket auto, which has driven double-digit growth across Elgin's Aftermarkets business which includes: (i) rebounds in vehicle traffic to pre-pandemic levels and (ii) an increase in Car Parc (registered vehicle population on the road) that is in the "sweet spot" for Elgin's products of 7 - 12 years old The Company's manufactured parts sold to OEMs are mostly used in heavy-duty diesel vehicles, which continue to have significant support and ongoing development from OEMs as heavy-duty vehicles are some of the OEMs' most profitable vehicle lines and are not easily addressed by electric vehicle technologies Sole supplier of pushrods for both of its two largest customers (two blue-chip OEMs) NYSE: MAIN Expansion into Big Box auto retail, opportunistic price increases and SKU expansion across current customer base and new customer additions are all tangible, organic growth opportunities for the Company's Aftermarket business to benefit from the favorable trends in the space Continued growth of OEM business with near term new customer additions and expansion mainstcapital.com#91Company Overview Over the last 100+ years, Elgin has evolved into a fully-integrated manufacturer and distributor of engine and chassis components to a highly attractive customer base of Aftermarket and OEM customers ■ ― - Elgin is a third-generation family-owned business led by Bill Skok and Tom Skok The Company manufactures four (4) types of parts for its OEM customers across automotive, industrial and commercial end-users: Engine Components: Pushrods, Rocker Arms, Piston Pins Chassis Components: King Pins Elgin also sells an assortment of engine and chassis components to the automotive Aftermarket, including: - All manufactured parts (listed above), valvetrain, timing, fluid management, suspension, steering, and a variety of other engine and chassis components Elgin employs 180 non-union employees and operates out of a ~130k sq. ft facility with manufacturing capabilities that include inline tube reducing, multi-axis machining and heat-treating capabilities amongst others - 100% of materials for the Company's manufactured products are sourced domestically with over 85% of total spend with its suppliers located in the United States Representative Customers Ford MOTOR? HARLEY-DAVIDSON CYCLES ASPERCOM ENGINES&TRANSMISSIONS Dayton Parts GO! ELGIN OEM 34% STELLANTIS JOHN DEERE SUMMIT RACING EQUIPMENT 2023 YTD Revenue by Segment JEGS Aftermarket 66%#92Company History 1919 Martin Skok founded Elgin in 1919 originally producing Aftermarket piston pins and selling 36,000 piston pins in the first year Skok quickly realized a shortfall existed in the entire Aftermarket space and began Elgin's expanding product offering ain Polits BEATMENT P ■ 1940s - 1950s Martin Skok's love for motorsports propelled the Elgin brand This eventually led to the Elgin Pro Stock line of products which were developed to support high-performance applications ELGIN PISTO Special 1980s - Present Reputation attracted ■ the attention of OEMs who valued Elgin's product expertise and product performance Under the leadership of Martin Skok Jr., Elgin continued to expand its OEM customer base and capabilities, complementing the Aftermarket business IHLUTINIAT PAUL RUSSO INDIANAPOLIS MOTOR SPEEDWAY -4940 38 (22) Spod ■ ELGIN Present 100+ year business with third-generation owners Tier 1 supplier to OEMs and Aftermarket business that supports over 45,000 SKUs Strong platform with many opportunities for future growth ELGIN MACHINE WORKS Inc. THE HOME OF ELTON Pins 10000 100#93Product Overview: Engine Components Pushrod Engine Camshaft Sprocket Key: Drive Chain FIGIN CA Bucket Tappet Pushrod Tappet Cam Rocker Arm Manufactured Parts sold to OEMs and Aftermarket Customers 3rd Party Manufactured Parts sold by Elgin to its Aftermarket Customers Valve Piston Pins Valve Spring I I I I I I | I I I Camshaft Sprocket T Dual Overhead Cam (DOHC) Engine Toothed Drive belt Camshaft Sprocket Cam ELGIN Valve Spring Camshaft Bucket Tappet Valve Piston Pins#94Pushrod Overview Benefits Prevent catastrophic failure ✓ Act as the "fuse" in the engine ✓ Designed to break to prevent other engine part failures ✓ Lighter and more compact (less space between cylinders) ✓ Low center-of-gravity ✓ Better low-end torque ✓ Inexpensive ✓ Compact size and low weight profile ✓ Increases towload/payload capacity with strong torque Pushrods Heavy Duty Trucks NAVISTAR CHENDRICKSON ✓ Automotive Ford gm ✓ Industrial JOHN DEERE ✓Powersports End Uses MOTOR? HARLEY-DAVIDSON CYCLES ELGIN#95Product Overview: Chassis Components Chassis Components Stabilizer Bar Lower Control Arm --- Upper Control Arm Upper Ball Joint Lower Ball Joint King Pins ELGIN ✓ Inventory of off-the shelf stock parts for both manufactured and distributed parts Customer catalogue of > 45,000+ SKUs ✓ Domestic supplier base helps to optimize quality and availability of products 95% fill rate to customer base Key: Manufactured Parts sold to OEMs and Aftermarket Customers 3rd Party Manufactured Parts sold by Elgin to its Aftermarket Customers#96Auto Aftermarket Industry Total Addressable Market ("TAM")(¹) Elgin's Aftermarket TAM is approximately $55+ billion, which includes $31 billion in the Do It For Me ("DIFM") market segment and $24 billion within the Do It Yourself ("DIY") segment ■ Favorable Car Parc Trends(²) ■ Elgin has significant opportunity to increase its market share by expanding into the big-box retailers ■ The car parc (registered vehicles on the road) is beginning to enter the Aftermarket "sweet spot", which is defined as vehicles between 7-12 years old Growth of the sweet spot is poised to sharply accelerate in 2022 and continue to grow at a solid pace over the next three years, which should provide a robust runway for category demand across the Aftermarket Big-Box Retailers DIFM Market Share Service Chains 20,000 18,000 16,000 14,000 12,000 10,000 8,000 6,000 4,000 2,000 0 44% 10% Cars entering the "Sweet Spot" ('000) 2015 2017 2019 46% 2021 Dealerships 2023E 2025E Big-Box Retailers 20,000 18,000 16,000 14,000 12,000 ELGIN 10,000 8,000 6,000 4,000 2,000 0 DIY Market Share (1) Source: Bank of America Equity Research - "The Owner's Manual 2021 - An Auto Aftermarket Primer" 2015 32% 2017 Cars exiting the "Sweet Spot" ('000) 68% 2019 Others 2021 2023E 2025E (2) Source: UBS Global Research - 2022 Auto Parts Outlook#97Management Team Name / Title Bill Skok President and Chief Executive Officer Tom Skok Chief Technology officer Chris Anderson Executive Vice President Marie Ziemba Chief Financial Officer ELGIN Background/Role Responsible for all executive decisions, strategy development and distribution Third generation President with a 37-year tenure at Elgin Bill is a past president of the National Engine Parts Manufacturer's Association and a board member of the Production Engine Remanufacturers Association Responsible for designing and programming all proprietary computer systems used by Elgin, including the Company's internally-developed business systems, paperless distribution and manufacturing systems, Warehouse Management System ("WMS") and e- catalog 41-year tenure at Elgin Degree in programming from DeVry University Responsible for overseeing all operations of Elgin World Trade (Export Business) Prior to EVP, Chris was the Export Sales Manager for 8 years and International Sales Supervisor for 6 years 22-year tenure at Elgin Responsible for all financial reporting, cash management and business planning 16-year tenure at Elgin Prior to joining Elgin, Marie was a director of financial operations for a plastics company#98Customer Channels: OEM OEM Operations OEMs operate in the automotive, commercial vehicle, powersport, and industrial equipment end markets ■ I OEMs make orders on a programmatic basis based on factory scheduled engine productions in which the Company is manufacturing on a built-to-order basis Elgin serves 9-10 OEM customers Ford Ⓡ JOHN DEERE ■ Pushrods Select Customers Rocker Arms CHENDRICKSON NAVISTAR Key Products STELLANTIS ELGIN ■ ■ Piston Pins King Pins MOTOR? HARLEY-DAVIDSON CYCLES GENERACⓇ PRO#99Awards and Certifications GMC gm GENERAL MOTORS CUSTOMER CARE AND AFTERSALES Certificate of Excellence PLATINUM Supplier Status is hereby granted to ELGIN INDUSTRIES ELGIN, IL In Recognition for Outstanding 2022 On-Time Shipping Performance to General Motors Customer Care and Aftersales Neather Lathan Heather Latham CCA Director of Supplier Management Yon Gober Kenneth Johns Director, CCA/Warranty Recovery, GPSC 2017 Supplier of the Year HAT INDUSTRIES JOHN DEERE JOHN DEERE Sevcellence 2017 Supplier of the Year ELGIN INDUSTRIES ELGIN IL And Ford Q1 FORD PREFERRED QUALITY STATUS IATF 16949 JOHN DEERE Tenth Consecutive Year Partner Level Supplier ELGIN PLUS INDUCTED 10 Year Supplier INTO THE Hall-of-Fame 4010 DIESEL ELGIN INDUSTRIES 000 ENVIA RONMENTAL ME MANAGEMEN ISO 14001 CERTIFIED SYSTEM#100Customer Channels: Aftermarket Customer Channel Engine Rebuilders (150+ Customers) Engine Rebuilders refurbish, fix, and repurpose existing internal combustion ("ICE") engines to resell in the Aftermarket for full / partial engine replacements Distributors / Manufacturers (225+ Customers) Warehouse distributors & buying groups serve professional mechanics, jobbers, auto parts stores, and e-commerce merchants ■ E-tailers (10+ Customers) Established relationships with an attractive group of e-tailers, including online merchants and national distributors Elgin's powerful brand is especially impactful in the e- commerce channel, as consumers prefer a brand they recognize when shopping online ■ Export (90+ Customers) Long-standing relationships in high-growth international markets Sales of heavy duty and auto chassis components to export regions including Latin America and the Middle East ■ Aless4.00 MARSHALL'S Automatic Mass LKQ LIBERTY ENGINE PARTS, INC. ENGINE PRO Select Customers PARTS FINDER SUMMIT RACING EQUIPMENT Saudi Arabia ELGIN Dayton Colombia ASPER.CO ENGINES & TRANSMISSIONS Engines Parts INTERNAL VEGE SPEEDWAY MEGS amazon motors. El Salvador Mexico#101Branded Products Overview Elgin Brand ■ Elgin's brands and products are the preferred choices of thousands of engine builders and automotive and heavy-duty vehicle service. professionals ELGIT INDUSTRIES Ses qusility pushred:" ze BET ML-2149 INT #ar800 ■ Elgin Pro Stock Using advanced metallurgies, ultra-modern design and construction, and made-in-the-USA quality, Elgin's PRO-STOCK parts provide a performance advantage to premier engine builders, racers, and enthusiasts 0894 ttts EndocĚFEE Elgin Black Ice & RxEMEDY ELGIN Black Ice: proprietary "super- cryogenic" heat treated engine components RXEMEDY: lubricants and additives specially formulated to enhance the value of every repair or performance upgrade BLACK ICE ELGIT REMEDY RE 21 men REMEDY ZOON ZDDP-4 PRIOW STOURY EMEDY#102Current Priorities and Growth Plans 1 Expansion Into New Channels (i.e. Big Box Aftermarket Retail) 2 3 4 5 Increase Production Capacity SKU Penetration With Current and New Customers Opportunistic SKU Expansion ELGIN Acquire and Grow New Product Lines#103喜 MAIN ST Main Street Capital Corporation CAPITAL CORPORATION Private Loan Investment Strategy June 2023 WA NYSE: MAIN mainstcapital.com#104Main Street's Private Loan Investment Strategy Investment Objective U.S. focused Private Loan strategy investing primarily in senior secured first lien loans of companies owned by or being acquired by Private Equity Sponsors (1) seeking capital for acquisitions, leveraged buyouts and recapitalizations Investment Criteria Primary Sectors: Business Services, Consumer, Food & Beverage, Healthcare, Industrials, Leisure / Entertainment, Tech / Software, Telecom and Media •● MAIN ST Lead/Co-Lead Investment Profile Target Market: Companies with $7.5 million to $50 million of EBITDA • Target Investment Loan Size: $20 million to $150 million CAPITAL CORPORATION • Target Securities: First Lien Loans, Unitranche Loans, Equity Co-Invest Target Return: 9.0% to 14.0%; subject to fluctuation based upon changes in underlying floating market index interest rates Risk Profile Seek to avoid: Distressed / stressed situations, highly cyclical / seasonal businesses, low margins, capital intensive businesses, high customer concentration, inexperienced management teams NYSE: MAIN Target loan tolerance factors: Total leverage range below 4.5x, debt to cash equity below 60%, demonstrated cash flow generation (1) Private Equity Sponsor includes (a) traditional private equity funds managed by a private equity firm and (b) family office or other institutional investors with an investment history and capabilities consistent with a private equity sponsor Main Street Capital Corporation mainstcapital.com#105What have we done over the last few years (1),(2)….. FY 2021 MAIN External Investment Adviser Clients Total FY 2020 $264.9mm Gross Originations $171.9mm Repayments $93.0mm Net Originations $33.3mm Gross Originations $119.6mm Repayments ($86.3mm) Net Originations $298.2mm Gross Originations • 11 new issuers - $223.5mm • 12 follow-ons - $74.7mm $291.4mm Repayments $6.7mm Net Originations $774.3mm Gross Originations $409.0mm Repayments $365.3mm Net Originations $528.0mm Gross Originations $143.3mm Repayments $384.7mm Net Originations $1,302.3mm Gross Originations 28 new issuers - $1,163.0mm 17 follow-ons - $139.3mm ● ● $552.3mm Repayments $750.0mm Net Originations $712.1 mm Gross Originations $407.2mm Repayments $304.9mm Net Originations FY 2022 $208.3mm Gross Originations $159.9mm Repayments $48.4mm Net Originations $920.4mm Gross Originations • 21 new issuers - $776.3mm 17 follow-ons - $144.1mm $567.2mm Repayments $353.2mm Net Originations ● NYSE: MAIN MAINST CAPITAL CORPORATION Q1 2023 $13.6mm Gross Originations $6.6mm Repayments $7.0mm Net Originations $15.4mm Gross Originations $2.1mm Repayments $13.3mm Net Originations $29.0mm Gross Originations 1 new issuer - $10.0mm • 3 follow-ons - $19.0mm $8.7mm Repayments $20.3mm Net Originations (1) Main Street Capital Corporation (MAIN) (2) Private Loans sourced by Main Street's Private Credit group and allocated to Main Street Capital Corporation (MAIN), MSC Income Fund (MSIF), MS Private Loan Fund I, LP (PLF) and other entities or investor capital managed by MAIN's External Investment Adviser Main Street Capital Corporation mainstcapital.com#106● Consistent Growth of Private Loan Assets Beginning in 2013, Main Street concluded that the direct lending opportunity was attractive and began to build and expand its Private Loan Investment Strategy Asset class can be difficult for most investors to access ● ● ($ in Millions) Opportunity to participate in an asset class with a history of delivering compelling risk-adjusted returns MAIN platform's Private Loan portfolio has experienced strong growth since 2013 - $67.7 million at YE 2013 to $2,238.9 million as of Q1 2023 Main Street Private Loan Assets Under Management (AUM)(1)(2) SMA ■PLF MSIF ■MAIN # of Loans $67.7 $677 2013 12 $162.8 $477 $115.2 2014 31 $216.5 $110.6 $105.9 2015 22 $373.3 $211.4 $161.9 2016 27 $616.2 $315.4 $300.8 2017 33 $820.4 $408.9 $411.5 2018 44 $1,101.1 NYSE: MAIN $481.1 $620.0 2019 52 $1,033.0 $342.8 $690.2 2020 53 $1,808.3 $101.3 $84.1 $537.9 $1,085.0 MAIN ST 2021 CAPITAL CORPORATION 64 $2,205.6 $112.3 $163.7 $511.9 $1,417.7 2022 76 $2,238.9 $112.3 $175.8 $516.2 $1,434.6 Q1 2023 77 (1) Private Loans sourced by Main Street's Private Credit group and allocated to Main Street Capital Corporation (MAIN), MSC Income Fund (MSIF), MS Private Loan Fund I, LP (PLF) and other entities or investor capital managed by MAIN's External Investment Adviser (2) All figures are calculated on a fair value basis Main Street Capital Corporation mainstcapital.com#107Record Private Equity Dry Powder Supports Continued Demand Outlook Dry powder statistics suggest significant additional capacity for direct lending strategy Direct lending dry powder in North America is currently $106 billion, which represents only 18% of PE buyout dry powder ● ● Dry Powder ($B) We believe scaled providers will benefit from the available capacity as PE is increasingly reliant on direct lending $800 $700 $600 $500 $400 $300 $200 $100 $0 1% North America Dry Powder - Direct Lending and PE Buyout ■ Direct Lending Dry Powder PE Buyout Dry Powder Direct Lending Dry Powder as a % of PE Buyout Dry Powder 1% 1% 3% Source: Preqin as of December 2022 Main Street Capital Corporation 11 6% 5% 6% 7% 2004 2005 2006 2007 2008 2009 2010 2011 10% 18% 14% L 12% NYSE: MAIN 13% 15% MAIN ST CAPITAL CORPORATION 17% 16% 17% 2012 2013 2014 2015 2016 2017 2018 2019 2020 20% 2021 18% 2022 mainstcapital.com#108Q Co-Lead 10.0% Private Loan Deal Flow (4), (5) How Does Main Street Access Private Loans? Private Loans are generated through existing Private Equity Sponsors (¹), co-lender or intermediary relationships Current Private Loan Activities (2), (3) Lead Lead 51.5% Co-Lender 28.0% Borrower Direct 1.0% Club 38.5% Intermediary 41.8% Private Equity Sponsor 29.2% ● ● ● ● ● ● MAIN ST CAPITAL CORPORATION Main Street wins deal through a competitive process or originates the deal directly through an existing relationship Holds lead underwriter role and closest relationship to private equity sponsors and company; may form club of co-lenders based on facility size and transaction dynamics Enables Main Street to have the most control over underwriting process, investment terms and conditions, and ongoing relationship with Sponsor Co-Lead Main Street sources an existing lender relationship or receives an inbound from a lender relationship looking for a partner Jointly submits an Indication of Interest (101) Main Street splits underwriting efforts while still maintaining control of the process Club Main Street receives inbound from perspective lender or intermediary forming a club of lenders Small lender group, typically 3-5 institutions Enables Main Street to participate in a smaller piece of the pie, providing portfolio diversification and reducing balance sheet risk (4) All Private Loans reviewed by Main Street's Private Credit group via Main Street's internal CRM system from 2013 through March 31, 2023 (5) Percentages calculated on a total number of transactions basis Main Street Capital Corporation NYSE: MAIN (1) rivate Equity Sponsor includes (a) traditional private equity funds managed by a private equity firm and (b) family office or other institutional investors with an investment history and capabilities consistent with a private equity sponsor (2) Current Private Loan portfolio closed by Main Street's Private Credit group and held in MAIN's investment portfolio as of March 31, 2023 (3) Percentages calculated based on cost as of March 31, 2023 mainstcapital.com#109Private Loan Strategy - Current Portfolio Strategy (1), (2) Lead 51.5% Security Type(1).(2) 1st Lien 97.9% СОО Equity 1.7% Other 0.4% Total Private Loan Portfolio: Average Net Leverage / Average & Median Adjusted EBITDA ($ in millions) $51.7 3.32x $25.7 FY 2018 Co-Lead 10.0% 3.84x $62.0 Club 38.5% $36.1 FY 2019 4.08x $57.7 $21.2 FY 2020 3.59x $39.4 $23.8 FY 2021 NYSE: MAIN Private Equity Portfolio Company Ownership (1), (2) Sponsor (3) 95.8% 3.49x $43.4 MAIN ST $21.0 CAPITAL CORPORATION FY 2022 3.56x $44.8 Sponsored (4) Non 4.2% $20.0 Q1 2023 Avg. EBITDA Median EBITDA Net Leverage (1) Current Private Loan portfolio closed by Main Street's Private Credit group and held in MAIN's investment portfolio as of March 31, 2023 Percentages calculated based on cost as of March 31, 2023 (2) (3) Private Equity Sponsor includes (a) traditional private equity funds managed by a private equity firm and (b) family office or other institutional investors with an investment history and capabilities consistent with a private equity sponsor (4) Owned by an individual(s) or any entity other than a Private Equity Sponsor Main Street Capital Corporation mainstcapital.com#110Lead 65.7% Private Loan Strategy - 2022 2023 New Originations Strategy (1), (2) Security Type(1), (2) Portfolio Company Ownership (1), (2) Private Equity Sponsor(³) 96.1% 1st Lien 98.4% O Q Q ($ in millions) $32.3 4.25x $22.4 Club 31.4% Q1 2022 Co-Lead 2.9% $33.2 New Private Loans: Average Net Leverage / Average & Median Adjusted EBITDA 5.40x $33.2 $21.4 Q2 2022 3.14x $15.2 Equity 1.6% NYSE: MAIN $30.8 MAIN ST 2.94x CAPITAL CORPORATION $25.1 $37.1 4.23x Q3 2022 Q4 2022 Avg. EBITDA Median EBITDA Net Leverage (1) Current Private Loan portfolio closed by Main Street's Private Credit group and held in MAIN's investment portfolio as of March 31, 2023 Percentages calculated based on cost as of March 31, 2023 (2) (3) Private Equity Sponsor includes (a) traditional private equity funds managed by a private equity firm and (b) family office or other institutional investors with an investment history and capabilities consistent with a private equity sponsor (4) Owned by an individual(s) or any entity other than a Private Equity Sponsor Main Street Capital Corporation Non Sponsored (4) 3.9% $33.4 Q1 2023 mainstcapital.com#111Track Record of Performance (1) Main Street has demonstrated an expertise in Private Loans MAIN ST Total Invested Capital Since Inception (2) Total # of Investments (3) Total # of Defaulted Loans(3), (4) Average Annualized Default Rate Since Inception (3) Realized Losses (3).(5) Average Annualized Realized Loss Rate Since Inception (3) Current Portfolio Average Stated Coupon (3). (6) Average Return on Assets Since Inception (3) CAPITAL CORPORATION Main Street Private Loan Investment Summary Performance Since 2013 through March 2023 $4.7 Billion 141 8 0.55% $32.5 Million 0.11% 10.86% 9.78% (1) All return information included is calculated on an unlevered basis (2) Private Loans sourced by Main Street's Private Credit group and allocated to MAIN, MSC Income Fund, Inc., MS Private Loan Fund I, LP and other entities or investor capital managed by MAIN's External Investment Adviser (3) Private Loans sourced by Main Street's Private Credit group and allocated to MAIN's investment portfolio (4) Includes investments placed on non-accrual, defaulted loans, and loans with realized losses (5) Non-Taxable Restructurings with Unrealized Losses are conservatively included in the group of investments that have incurred Realized Losses although these investments have not resulted in a realized loss for GAAP or tax accounting purposes as of March 31, 2023 (6) Current Private Loan portfolio sourced by Main Street's Private Credit group and allocated to MAIN's investment portfolio as of March 31, 2023 Main Street Capital Corporation NYSE: MAIN mainstcapital.com#112Private Loan Returns 10.9% 8.6% 6.5% FY 2017 8.7% 8.1% 9.3% FY 2018 12.8% Total Returns (1), (2), (3) vs. Indices 9.1% 9.0% FY 2019 ■MAIN Private Loans 5.0% 5.5% 8.3% 10.6% 12.8% FY 2020 Cliffwater Direct Lending Index 12.2% FY 2021 8.2% 6.3% Senior BDCs 7.1% FY 2022 MAIN ST CAPITAL CORPORATION 8.5% 7.3% 6.3% Q1 2023 (1) Total return includes interest, fee, and dividend income plus realized and unrealized gains and losses for the last twelve months (2) Represents Private Loans sourced by Main Street's Private Credit group and allocated to Main Street's investment portfolio (3) Senior BDCs is average Total Asset Return for Golub (GBDC), Goldman Sachs (GSBD), Carlyle (CGBD), Pennant Park Floating (PFLT), and Oaktree Specialty Lending (OSCL) BDCS Main Street Capital Corporation NYSE: MAIN mainstcapital.com#113Middle Market Strategy - Current Portfolio Strategy(1).(2) Security Type(1).(2) Syndicated 93.3% a a Other 0.9% Total Middle Market Portfolio: Average Net Leverage / Average & Median Adjusted EBITDA ($ in millions) 3.62x $92.3 $64.7 FY 2018 Club 6.7% 3.75x $84.3 $63.1 FY 2019 1st Lien 93.0% 3.83x $77.6 $60.3 FY 2020 $74.2 Equity 3.92x 6.1% NYSE: MAIN $51.1 FY 2021 Portfolio Company Ownership (1), (2) Private Equity Sponsor (3) 85.0% 4.65x $85.7 MAIN ST $47.1 CAPITAL CORPORATION FY 2022 Non Sponsored (4) 15.0% 4.52x $87.2 $47.3 Q1 2023 Avg. EBITDA Median EBITDA Net Leverage (1) Current middle Market portfolio closed by Main Street's Private Credit group and held in MAIN's investment portfolio as of March 31, 2023 (2) Percentages calculated based on cost as of March 31, 2023 (3) Private Equity Sponsor includes (a) traditional private equity funds managed by a private equity firm and (b) family office or other institutional investors with an investment history and capabilities consistent with a private equity sponsor (4) Owned by an individual(s) or any entity other than a Private Equity Sponsor Main Street Capital Corporation mainstcapital.com#114Middle Market Returns 8.1% 5.0% FY 2017 4.6% 1.3% FY 2018 LTM Total Returns (1), (2) vs. Indices 1.2% 8.3% FY 2019 ■MAIN Middle Market 1.7% FY 2020 -0.7% 8.4% (1) Total return includes interest, fee, and dividend income plus realized and unrealized gains and losses (2) Represents Middle Market investments sourced by Main Street's Private Credit group and allocated to MAIN's investment portfolio Main Street Capital Corporation NYSE: MAIN CS Leveraged Loan Index - B Ratings 5.1% FY 2021 MAIN ST CAPITAL CORPORATION 1.2% 0.0% FY 2022 mainstcapital.com#115Private Loan Case Study - Klein Hersh (Lead Loan) $85.0 Million November 13, 2020 Senior Secured Credit Facility Kleintersh Strategic Leadership Placement N STATE CAPITAL PARTNERS Sole Arranger MAIN ST CAPITAL CORPORATION ● ● Note: Past performance does not guarantee future results Main Street Capital Corporation MAIN ST CAPITAL CORPORATION Transaction Overview On November 13, 2020, Klein Hersh LLC (KH) closed an $85.0 million senior secured credit facility consisting of: $5.0 million cash flow Revolver (pari with the First Lien Term Loan, undrawn at close) $80.0 million First Lien Term Loan (the Term Loan) Main Street served as the sole lead arranger in the financing process At close, Main Street held $2.5 million of the cash flow Revolver and $40.0 million of the Term Loan while syndicating the remaining $2.5 million of the Revolver and $40.0 million of the Term Loan to two other parties Shortly after close, Main Street sold $5.0 million of the Term Loan bringing its total hold size to $37.5 million of the credit facility Main Street generated $250K in syndication fees through this transaction Sourced from an Intermediary relationship On April 27, 2022, KH paid off the Main Street credit facility, with the investment yielding a 16.1% annualized Internal Rate of Return, or IRR, and 1.13x Multiple on Invested Capital Company Overview KH is an executive search placement firm focused on the health care and life sciences industries; KH has become a trusted advisor to leading global pharma, emerging biotech and life sciences-focused PE / VC firms KH has a distinct culture and a business model incorporating three to four touch points with different account executives in every search that separate it from its competitors NYSE: MAIN mainstcapital.com#116Private Loan Case Study - VORTEQ (Lead Loan) $55.0 Million November 30, 2021 Senior Secured Credit Facility Q VORTEQ SHADOWBRIAR CAPITAL PARTNERS Sole Arranger MAINST CAPITAL CORPORATION Note: Past performance does not guarantee future results Main Street Capital Corporation MAIN ST Transaction Overview On November 30, 2021, VORTEQ closed a $55.0 million senior secured credit facility consisting of: ● CAPITAL CORPORATION $5.0 million priority Revolver (undrawn at close and held by TriState Capital) $50.0 million First Lien Term Loan (the Term Loan) Main Street served as the sole direct lender and arranger in the acquisition process At close, Main Street held $26.0 million of the Term Loan and funds managed by Main Street held $24.0 million of the Term Loan In conjunction with the Term Loan, Main Street and the funds managed by Main Street participated in equity co-invest of $1.0 million and $1.0 million, respectively Main Street allocated $4.8 million of the Term Loan and ~$0.2 million of the equity co- invest to Private Loan Fund I on the November 30th close On December 6, 2022, VORTEQ paid off the Main Street credit facility, with the investment yielding a 12.9% annualized Internal Rate of Return, or IRR, and 1.13x Multiple on Invested Capital Main Street and the funds managed by Main Street remain in the equity co- invest, with the fair value of such equity appreciating in fair value given VORTEQ's positive operating performance Company Overview VORTEQ was founded in 1982 under the name Wismarq, before taking the name VORTEQ in 2017 following the acquisition by Peninsula Pacific; the Company performs specialty coating of aluminum and steel for customers which primarily operate in the construction, home improvement, and vehicle industries with a nationwide network of seven coil coating facilities and nine coating lines The Company has expanded its geographic footprint through the acquisition of new plants including facilities in Woodstock, IL and Rancho Cucamonga, CA in 2018 and 2019, respectively, as well as a 2022 acquisition of a paint line in Mexico NYSE: MAIN mainstcapital.com#117Private Loan Case Study - NWN (Lead Loan) $247.0 Million May 7, 2021 Senior Secured Credit Facility nwn N STATE CAPITAL PARTNERS Sole Arranger MAIN ST CAPITAL CORPORATION Note: Past performance does not guarantee future results Main Street Capital Corporation MAIN ST Transaction Overview On May 7, 2021, NW N Corporation (NWN) closed a $247.0 million senior secured credit facility consisting of: ● CAPITAL CORPORATION $30.0 million cash flow Revolver (pari with the First Lien Term Loan, undrawn at close) $217.0 million First Lien Term Loan (the Term Loan) Main Street served as the sole lead arranger in the financing process At close, Main Street held $20.2 million of the Revolver and $124.3 million of the Term Loan and funds managed by Main Street held $3.5 million of the Revolver and $46.5 million of the Term Loan while syndicating $6.0 million of the Revolver and $44.0 million of the Term Loan to three other parties Shortly after close, Main Street sold $11.4 million of the Revolver and $94.5 million of the Term Loan to group of direct lenders via assignment Main Street generated $1.1 million in syndication fees through this transaction Main Street allocated $2.2 million of the Term Loan and $0.3 million of the cash flow Revolver to Private Loan Fund I (Fund I) on the May 7th close After closing, (i) Main Street held $41.2 million of Term Loan and ~$8.8 million of the Revolver, (ii) Fund I held $2.2 million of the Term Loan and ~$0.3 million of the Revolver and (iii) other funds managed by Main Street held $3.5 million of the Revolver and $46.5 million of the Term Loan Company Overview NW N is a leader within the business and managed services space providing secure cloud communications, security, unified communications and collaboration, data center, networking, managed services and cloud solutions NW N has an attractive 40% managed services / 60% product revenue mix which drives margin expansion and has exposure to attractive end markets including commercial, education, financial, government, healthcare, and industrial; NW N is headquartered in Waltham, MA NYSE: MAIN mainstcapital.com#118$155.0 Million Private Loan Case Study - South Coast Terminals (Lead Loan) Transaction Overview On December 13, 2021, South Coast Terminals (SCT) closed a $155.0 million senior secured credit facility consisting of: December 13, 2021 Senior Secured Credit Facility G SouthCoast ዋ PLATFORM PARTNERS Sole Arranger MAIN ST CAPITAL CORPORATION MAIN ST CAPITAL CORPORATION Note: Past performance does not guarantee future results Main Street Capital Corporation $15.0 million cash flow Revolver (pari with the First Lien Term Loan, undrawn at close) $140.0 million First Lien Term Loan (the Term Loan) Main Street Capital served as the sole lead arranger in the financing process At close, Main Street held $5.4 million of the Revolver and $50.7 million of the Term Loan and funds managed by Main Street held $4.7 million of the Revolver and $44.2 million of the Term Loan while syndicating $4.8 million of the Revolver and $45.2 million of the Term Loan to two other parties In conjunction with the credit facility, Main Street and funds managed by Main Street participated in equity co-invest of ~$0.9 million and ~$0.1 million, respectively Shortly after close, Main Street sold $1.0 million of the Revolver and $9.0 million of the Term Loan to a direct lender via assignment Main Street generated $100K in syndication fees through this transaction Main Street allocated ~$0.5 million of the Revolver, $4.5 million of the Term Loan, and -$75.8K of the equity co-invest to Private Loan Fund I on the December 13th close Company Overview SCT is one of the largest independent contract manufacturers of specialty chemicals and lubricant additives with three locations on the Gulf coast; SCT provides services ranging from chemical processing, and warehouse handling SCT has successfully built out blending facilities that are equipped to handle the long-term production of certain lubricants and additives; this has allowed SCT to invest in capex to commercialize existing products and develop the back-end for new products and establish long- standing customer contracts with the major specialty chemical players NYSE: MAIN mainstcapital.com#119Private Loan Case Study - Exostar (Co-Lead Loan) July 6, 2020 ● $65.0 Million Senior Secured Credit Facility EXOSTARⓇ We build trust. THOMABRAVO MAINST CAPITAL CORPORATION Note: Past performance does not guarantee future results Main Street Capital Corporation MAIN ST Transaction Overview On July 6, 2020, Exostar closed a $65.0 million senior secured credit facility consisting of: • CAPITAL CORPORATION $5.0 million cash flow Revolver (pari with the First Lien Term Loan, undrawn at close) $60.0 million First Lien Term Loan (the Term Loan) Main Street and Goldman Sachs Asset Management (Goldman) served as the direct lenders and the deal was sponsored by Thoma Bravo At close, Main Street held $1.25 million of the Revolver and $15.0 million of the Term Loan Goldman held the remaining $3.75 million of the Revolver and $45.0 million of the Term Loan Company Overview Exostar, headquartered in Herndon, VA, provides cloud-based solutions for multi-organizational collaboration, information sharing, value chain management and supply chain management Exostar offers identity credentialing, access management, assessment, implementation and customer support services to companies in highly regulated industries including aerospace & defense, healthcare, pharmaceutical, life sciences and financial services NYSE: MAIN mainstcapital.com#120Private Loan Case Study - Aspira (Club Loan) $162.0 Million April 8, 2021 Senior Secured Credit Facility ASPIRA. CONNECTED EXPERIENCES ALPINE MAIN ST CAPITAL CORPORATION MAIN ST Note: Past performance does not guarantee future results Main Street Capital Corporation CAPITAL CORPORATION Transaction Overview On April 8, 2021, Aspira closed a $162.0 million senior secured credit facility consisting of: $10.0 million cash flow Revolver (pari with the First Lien Term Loan, undrawn at close) $152.0 million First Lien Term Loan (the Term Loan) An existing co-lender relationship approached Main Street to gauge our interest in the financing opportunity Main Street served as a participant in a club of lenders At close, Main Street held $1.3 million of the Revolver and $19.4 million of the Term Loan and a fund managed by Main Street held $1.2 million of the Revolver and $18.8 million of the Term Loan Main Street allocated $2.2 million of the Term Loan and ~$0.1 million of the Revolver to Private Loan Fund I on the April 8th close Company Overview Aspira is the leading software solution provider used to manage outdoor recreation resources and to connect consumers with outdoor experiences Aspira offers an end-to-end technology platform, powering outdoor activities for federal, state and provincial, and local government parks, private campgrounds, and hunt and fish management agencies using Reserve America.com, the largest online consumer marketplace for camping reservations, as well as powering transactions directly on park agency sites NYSE: MAIN mainstcapital.com#121Main Street Capital Corporation Paul Gatti Chief Executive Officer CompareNetworks Diego Fernandez Managing Director Main Street Capital Corporation MAINST NYSE: MAIN CAPITAL CORPORATION mainstcapital.com#122Main Street's View of Transaction and Background Headquarters San Francisco, California Business Business to business media and technology company connecting practitioners in the science, healthcare, and industrial spaces with product manufacturers via generated qualified sales leads Website www.comparenetworks.com Original Investment Date January 2019 Investment Type First lien, senior secured term loan Majority equity investment Transaction Type Majority Recapitalization, Management Buyout Original Capital Invested $11.0 million total (100% MAIN) $9.0 million senior debt $2.0 million equity ● ● Additional Capital Invested $2.0 million total (100% MAIN) $2.0 million senior debt to support the Global Spec acquisition Overview Founded in 2000, Compare Networks, Inc. ("CompareNetworks" or the "Company"), is a leading provider of media, marketing, and technology solutions that drive revenue for life science, healthcare product manufacturers, and engineering firms across several proprietary platforms ■ ■ ■ CompareNetworks Attractive Recuring Revenue Model with Diversified Blue-chip Customer Base The Company provides advanced marketing solutions to an array of blue-chip customers that are leaders in the life sciences, industrial, healthcare, chemistry, and applied sciences laboratory products markets I The Company provides life scientists, researchers, lab-based professionals, pharmaceutical professionals, healthcare professionals, and engineers with digital tools and information resources on these platforms to research, identify, and determine which products and technologies to use, resulting in the generation of qualified leads and eventual product sales for advertisers I Compare Networks operates several online platforms including, but not limited to: Biocompare, the leading online research tool database; Labcompare, a leading online laboratory equipment product comparison service; and GlobalSpec, an online parts spec database providing engineers with parts data, relevant news, articles, and engineering datasheets; The Company also provides a software-as-a-service sales enablement tool named imSMART Alignment with Motivated, Experienced Management Team The initial transaction was to structured to allow the existing members of management to increase or acquire ownership interests in the Company via (i) rollover or cash contribution at close and (ii) through an equity incentive plan designed to allow management to participate in the equity upside of growth experienced by CompareNetworks Compare Networks benefits from contracted, recurring revenue derived from annual fixed-fee product listing contracts, pay per click product listings, banner advertisements, email blasts, and other direct engagement solutions Since closing, the management team has benefitted from the growth of the business through the execution of organic and inorganic initiatives and through the establishment of a scheduled dividend plan 2#123Business Overview ● ● ● Founded in 2000 Headquartered in San Francisco, California 153 employees Compare Networks' products include vertical marketplaces, email, video, print publications, and other media that assist manufacturers and marketers of life science tools generate qualified sales leads The Company's services help science, engineering and healthcare professionals solve important issues including, but not limited to: ● ● @ Email Mobile Finding cures for diseases Improving drug production Remediating environmental damages Improving food supply chain safety and transparency Mediums Served Print Graphic Ads Editorial Directory Social Video 3 oc Biocompare labcompare Forensic On the Scene and In the Lab Representative Brands SEQanswers the next generation sequencing commun Pharmaceutical Outsourcing™ ニニニニコ I GlobalSpec scilan Tablets & Capsules CompareNetworks American Pharmaceutical | Powered by GlobalSpec Review Electronics 360 OPHTHALMOLOGY WEB American Laboratory® ECOLAB Thermo Fisher SCIENTIFIC i imsmart Laboratory Equipment Denotes brands acquired following Main Street partnership Representative Customers dentalcompare Agilent Technologies Roche abcamⓇ +700 Other Customers BIO RAD DigiKey M MOUSER#124Lead Generation Funnel / Purchase Process Low Conversion Rate High I Awareness News, Editorial Content, Interactive Content Hubs, Custom Content Exploration Banner Ads, e-Newsletters, Email Blasts, Webinars, Videos Evaluation Product Directory, Product Reviews, Citations Decision Request Quote Purchase 4 CompareNetworks CompareNetworks provides science, engineering, healthcare, and laboratory professionals with a complete collection of media resources that connect buyers and sellers through all stages of the purchase process through qualified lead generation Website visitors are typically seeking to compare options, learn about new vendors, and efficiently assess options through one comprehensive comparison tool Through the services provided by each media platform, the Company helps hundreds of thousands of its platform's users focus on key issues that impact purchasing decisions#125Market Platforms Platform loc ac Biocompare GlobalSpec American Laboratory labcompare American Pharmaceutical Review Pharmaceutical Outsourcing™ 'OPHTHALMOLOGY WEB dentalcompare imsmart Markets Served ● ● ● ● ● ● ● ● ● . ● ● ● ● Life Sciences Tools & Equipment Drug Discovery Tools & Equipment Engineering Specifications Electronics Industrial Clinical Diagnostics Analytical Chemistry Materials Testing Life Sciences Tools & Equipment Drug Development / Manufacturing Quality Assurance / Control Clinical Trials Validation Eye Care Products Oral Care Products Mobile Sales Enablement Life Sciences / Healthcare Marketing 5 Key Advertisement Solutions Product Listings Email Blasts, Newsletters Online Advertising Content Hubs ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● Product Listings Content Hubs Email Blasts, Newsletters Webinars Product Listings Print / Direct Mail Online Advertising Email Blasts, Newsletters Online Advertising Email Blasts, Newsletters Print / Direct Mail Product Listings Email Blasts, Newsletters Video and Webinars Product Listings Email Blasts, Newsletters Video and Webinars CompareNetworks Software-as-a-Service Content Platform#126| Company History & Financial Performance I I 1 I I 2000 Compare Networks is founded by Paul Gatti, Andy Miller, and Mike Okimoto 2000 100.0% 2018 2005 Development of DentalCompare 2007 Development of Oweb 97.8% 2019 2005 Trailing Twelve-Month Revenue CAGR 22.5% 2008 Private equity firm acquires majority ownership stake in the Company 2010 Acquires American Laboratory 210.8% 2020 214.7% 2021 Key Historical Events 2012 Development of imSMART 2010 2011 Acquires American Pharma Review and 225.0% 2022 2015 Pharmaceutical Outsourcing Historical Financial Performance 6 100.0% 2017 imSMART expands internationally through its customer base 2018 2019 Main Street partners with the Company's management team to buy out non- management owners 2020 Acquires GlobalSpec 110.0% 2020 2019 CAGR 19.9% Trailing Twelve-Month Adjusted EBITDA 156.9% CompareNetworks 2020 2021 Acquires Tablets & Capsules and Chromocyte 2022 Acquires Facten Scilan 2023 221.0% 2021 206.8% 2022#127Current Priorities and Growth Plans 1 2 3 4 5 Increase Email Audience, Sophistication, and Automation Introduce Al Technology and Refine Search Engine Optimization New Customer Acquisition Acquire, Integrate, and Grow New Brands Shared Services and Operating Leverage CompareNetworks 7#128Historical Performance & Valuation (Equity Cost and FV $ in millions) $20.0 $15.0 $10.0 $5.0 $0.0 $2.0 $2.0 Transaction Date $2.0 $3.0 w ********* ** **** 22222 *xxx Dec-19 Equity Cost ($) $2.0 $6.8 Hot Dec-20 (A) -Q3 2020 Acquisition of GlobalSpec division is completed, bolstering the Company's EBITDA profile ...... **** $2.0 $8.3 Mar-21 www.Equity Fair Value ($) Q3 2020 Q2 2020-Q4 2022 (A) 个 (B) 个 $2.0 $10.0 ******** Jun-21 ******** ********* $12.0 $2.0 +5 ****** M Sep-21 ***** ****** ****** ******** $2.0 $12.0 8 M .......... ..... ******* *****..... ****** bemor **** ********* Dec-21 www. (B)-Q2 2020-Q4 2022 The digital verticals of Compare Networks benefit from COVID-19 pandemic as less conferences are held in person, shifting advertisement spend to higher margin, digital channels $13.6 ***** -2222 ***** ****** ********* *xx. **** ************ Mar-22 ******* wwwwww n**** www with ***** $2.0 $17.2 *** WAY. Adj. TTM EBITDA Growth % (from Transaction Date) ***** Jun-22 ***..... ....….... $18.6 $2.0 ***** MS JE ***** ****** ****** Sep-22 ******* ......... $2.0 $19.8 M CompareNetworks 9.15.00 **** ....... trees w ******.. ******* b www. Dec-22 $2.0 $18.4 Mar-23 Net Debt to Adj. TTM EBITDA as a % Q1 2023 (C)个 350% 325% 300% 275% 250% 225% 200% 175% 150% 125% 100% 75% 50% 25% 0% (C) - Q1 2023 As the digital vertical performance weakens due to the return of in-person conferences, the Company shifts its priorities and focus on other high demand marketing services and automation of its adjacent platforms#129喜 MAINST Main Street Capital Corporation CAPITAL CORPORATION Asset Management Business June 2023 T WA NYSE: MAIN mainstcapital.com#130Asset Management Business MAIN (1) is focused on growing its asset management business (AMB) MAIN'S AMB represents additional income diversification and the opportunity for greater shareholder returns MAIN's internally managed operating structure provides MAIN's shareholders the benefits of this AMB Growth of the AMB is increasingly driven by MAIN's Private Loan (PL) investment strategy MAIN (¹) is the investment adviser to and administrator of MSC Income Fund, Inc., a non-listed BDC with investment strategies consistent with MAIN MAIN (1) is the investment advisor to and administrator of MS Private Loan Fund I, LP, a private debt fund with investments solely focused on MAIN's Private Loan (PL) investment strategy MAIN (¹) manages a separately managed account solely focused on MAIN's PL investment strategy ● Benefits to MAIN Highly predictable source of recurring base management fee income No significant increases to MAIN's operating costs to provide services (leverage fixed costs and utilize existing infrastructure and investment capabilities) ● • Opportunity to capture upside of positive investment performance through incentive fees ● ● MAIN ST Monetizing the value of MAIN franchise Significant positive impact on MAIN's financial results CAPITAL CORPORATION - $8.1 million contribution to net investment income in the first quarter of 2023 (2) $22.3 million contribution to net investment income in the year ended December 31, 2022(2) $103.2 million of cumulative unrealized appreciation as of March 31, 2023 NYSE: MAIN (1) Through MSC Adviser I, LLC (the External Investment Manager), MAIN's wholly owned unconsolidated registered investment adviser subsidiary (2) Contribution to Net Investment Income includes (a) dividend income received by MAIN from the External Investment Manager and (b) operating expenses allocated from MAIN to the External Investment Manager Main Street Capital Corporation mainstcapital.com#131MSC Income Fund - Background MSC Income Fund (MSIF) is a non-listed BDC MAIN (1) historically was the subadviser to MSIF's former adviser MAIN (1) became the sole adviser to MSIF in October 2020 ● Since becoming the sole adviser to MSIF(¹) in October 2020, we have accomplished the following: ● MAIN ST CAPITAL CORPORATION Addressed MSIF's capital structure limitations MAIN provided an initial debt financing solution Facilitated new special purpose vehicle (SPV) financing arrangement to replace historical SPV Reinstated MSIF's co-investment activities with MAIN Reinstated shareholder dividends which currently represent an annual dividend equal to MSIF's historical annualized dividend rate paid prior to suspending the dividends in July 2020 Obtained investment grade debt rating and further strengthened MSIF's capital structure Unsecured long-term debt issuance in October 2021 (1) Through MSC Adviser I, LLC (the External Investment Manager), MAIN's wholly owned unconsolidated registered investment adviser subsidiary Main Street Capital Corporation NYSE: MAIN Achieved a "fully invested" portfolio based on MSIF's existing capital structure mainstcapital.com#132MSC Income Fund - Recent Activity and Achievements MSC Income Fund (MSIF) is a non-listed BDC Current focus on maximizing returns and providing liquidity options for MSIF shareholders Main Street Capital Corporation • Q1 2023 (annualized) - 8.0% Q4 2022 (annualized) - 8.1% • 2022 FY - 7.5% MAIN ST Generated favorable returns, with Return on Equity as follows: CAPITAL CORPORATION Generated Net Investment Income (NII) sufficient to pay annualized dividend of $0.70 per share, consistent with MSIF's highest historical dividend payment Executed Modified Dutch Auction Tender Offer in June 2023 to provide: Liquidity option to those MSIF shareholders with significant need or desire for liquidity NYSE: MAIN Opportunity for net asset value (NAV) appreciation for all MSIF shareholders Information regarding the liquidity desires of the MSIF shareholder base mainstcapital.com#133Non-Listed BDC Performance - 1 Year 4.17% ADS 6.09% HPSCL 8.63% ORIC 1 Year Ending March 31, 2023 - Annualized Return (¹) NM BSPC NM ORTI 5.32% BRPC NM OSC Source: The IPA / Stanger Monitor Report - as of March 31, 2023 (1) Calculated as: (Ending NAV + Cash Distributions) / (Beginning NAV) - compounded quarterly (2) NM Not in existence for full period Main Street Capital Corporation 7.72% MSIF NYSE: MAIN 8.00% ORCC II 11.22% FS E&P 5.33% FBSP MAIN ST CAPITAL CORPORATION NexPoint PF R&A -9.08% -17.78% mainstcapital.com#134Non-Listed BDC Performance - 3 Year NM ADS NM HPSCL NM ORIC 3 Year Ending March 31, 2023 - Annualized Return (¹) NM BSPC NM ORTI NM BRPC NM OSC Source: The IPA / Stanger Monitor Report - as of March 31, 2023 (1) Calculated as: (Ending NAV + Cash Distributions) / (Beginning NAV) - compounded quarterly (2) NM Not in existence for full period Main Street Capital Corporation 6.51% MSIF NYSE: MAIN 10.35% ORCC II FS E&P -9.29% 5.44% MAIN ST CAPITAL CORPORATION 10.01% 5.39% FBSP NexPoint PF R&A mainstcapital.com#135Non-Listed BDC Performance - 5 Year NM ADS NM HPSCL NM ORIC 5 Year Ending March 31, 2023 - Annualized Return (¹) NM BSPC NM ORTI NM BRPC NM OSC Source: The IPA / Stanger Monitor Report - as of March 31, 2023 (1) Calculated as: (Ending NAV + Cash Distributions) / (Beginning NAV) - compounded quarterly (2) NM Not in existence for full period Main Street Capital Corporation 6.49% MSIF NYSE: MAIN 7.34% ORCC II FS E&P -6.50% 4.98% FBSP MAIN ST CAPITAL CORPORATION NexPoint PF R&A -4.88% -6.61% mainstcapital.com#136Other Asset Management Business Activities MS Private Loan Fund I (PLF I) is a private partnership solely focused on executing co-investments with MAIN in its Private Loan (PL) investment strategy MAIN (1) maintains a relationship with an institutional investor through which MAIN (1) provides co-investment opportunities in MAIN's PL investment strategy MS Private Loan Fund II (PLF II), a successor fund to PLF I, is currently in the fundraising process ● MAIN (1) launched PLF I in December 2020 Solely focused on co-investments with MAIN in its PL investment strategy ● • $100+ million of equity capital ● Special purpose vehicle (SPV) financing with $125 million of debt capital Active co-investments with MAIN in all PL investments ● ● ● ● ● ● MAIN ST MAIN (1) established separately managed account (SMA) relationship in April 2021 CAPITAL CORPORATION ● ● Inception to date returns (Return on Equity) in excess of original target range of 8% to 12% MAIN (1) receives annual asset management fee and incentive fee above a required return Current performance is generating incentive fees for MAIN (¹) Long-term, established relationship SMA is solely focused on co-investments with MAIN in its PL investment strategy; subject to investor approval Expecting first closing on PLF II in the near-term future Successor fund to PLF I with identical investment strategy and same terms and conditions Goal for increased size of equity capital relative to PLF I MAIN (1) receives annual asset management fee and incentive fee above a required return (1) Through MSC Adviser I, LLC (the External Investment Manager), MAIN's wholly owned unconsolidated registered investment adviser subsidiary Main Street Capital Corporation NYSE: MAIN mainstcapital.com#137Main Street Capital Corporation C Chris Pace Founder and Chief Executive Officer Centre TECHNOLOGIES Damian Burke Managing Director Main Street Capital Corporation MAINST NYSE: MAIN CAPITAL CORPORATION mainstcapital.com#138I Headquarters Houston, Texas Business Provider of managed IT services for clients throughout Texas I Website Centre TECHNOLOGIES www.centretechnologies.com Original Investment Date January 2019 Investment Type First lien, senior secured term loan Minority equity investment Transaction Type !Minority Recapitalization ● Original Capital Invested (1) $22.6 million total ● Main Street's View of Transaction and Background Company Overview ▪ Centre Technologies ("Centre" or the "Company") provides information technology ("IT") hardware and software solutions for small and medium sized businesses and often functions as its client's IT department ● Additional Capital Invested (²) $7.9 million total ● $15.3 million senior debt $7.3 million equity $7.5 million senior debt $0.4 million equity To support acquisition growth I strategy (1) Main 80% / MSC Income Fund ("MSIF") 20% (2) Main 80%/MSIF 20%; invested in 2022 Main Street Capital Corporation MAIN ST CAPITAL CORPORATION ▪ Centre's "C-Stack" suite of solutions is a unique combination of product offerings and consultative services that cater to businesses' specific IT hardware, software, support, security and infrastructure needs Attractive Customer and Recurring Revenue Profile ▪ The level of service, integration into the client, and multi-year recurring contracts create a strong customer relationship and consistent revenue streams ▪ Centre has high customer retention rates when compared to industry averages and monthly recurring revenue ("MRR") has increased significantly since MAIN's investment Strong Market Position and Reputation ■ Centre is one of the leading, premium providers of IT services in Texas, serving small and medium sized businesses with enterprise level services, and has a well-earned reputation for excellent customer service ▪ Centre was recognized on Computer Reseller News' ("CRN") 2023 Tech Elite 250 as a top Managed Service Provider in North America Alignment with Dedicated, Driven Management Team ▪ The initial transaction structure and ongoing equity incentive plan are designed to maximize the alignment of interests between Centre's leadership team and Main Street NYSE: MAIN ▪ Main Street values the expertise of the leadership team and views them as critical for the continued owth of the Company and has supported the team in its recent acquisition of two Texas based IT services companies mainstcapital.com#139Company Overview | Business Overview Founded in 2006, Center has grown organically and inorganically to become a leading provider of IT services to small and medium sized businesses in Texas ■ ■ ■ ~200 employees; headcount has doubled since Main Street's initial investment Majority of revenue is MRR driven by a focused growth strategy in its Managed Services segment(¹) Completed two strategic acquisitions in Austin and San Antionio in 2Q22 that provided geographic /product/customer expansion with strong MRR The Company continues to look for organic and in-organic growth opportunities throughout Texas and neighboring states Revenue by Business Segment Managed Services Hardware / Software IT Consulting (1) Managed Services include managed IT services and cloud services Revenue by Geography Austin Centre TECHNOLOGIES San Antonio Dallas Houston#140Company Overview | Timeline 2006 Founded by Chris Pace in 2006 with an initial focus on hardware & software sales 2016 2010 Centre introduced its Managed Services segment and announced a partnership with Dell as a Value-Added Partner Acquires Tradentrix and Architel, based in Houston and Dallas, respectively, to enhance managed services and expand geographic reach in Dallas Historical Timeline 2017 Centre, after acquiring Tradentrix, expanded the executive management team as it looked to spearhead its next phase of growth Acquisition Timeline 2022 Centre acquires Texas Systems Group and Commercial IT, based in Austin and San Antonio, respectively, to expand geographic reach in both cities and enhance managed service capabilities 2019 Main Street acquires a minority stake in Centre Technologies in January 2019 as part of a minority recapitalization 2022 2023 Record financial performance including 46% growth in proforma revenue and 69% growth in proforma EBITDA since the Original Investment Date; Continue to grow MRR and market share in Texas Centre TECHNOLOGIES Centre continues to evaluate additional add- on opportunities across Texas as part of its strategic plan#141Company Overview | The Outsourced IT Department IT Department Security Monitoring Reporting Recommendations Optimization Admin Support End User Support Secure Co- Managed Services (SMS-CO) Proactive Secure Managed Services (SMS) Secure Microsoft 365 (M 365) Proactive Requires SMS Backup and Disaster Recovery (BDRaaS) Reactive Cloud Desktops (VDI / DaaS) Requires SMS Microsoft Azure and AWS (IaaS) Reactive Note: Green dots represent current capabilities; Requires SMS signifies clients must have multifactor authentication enabled SIMPLIFYING WHAT WE DELIVER Managed Vulnerability Scanning (MVS) Centre TECHNOLOGIES Managed Detection and Response Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS Requires SMS#142Company Overview | MRR Growth Transaction Date Managed Services (1) Proforma for 2022 acquisitions Growing Recurring Client Relationships MRR: ~166% Growth Hardware / Software TTM 3/31/2023(1) IT Consulting Centre TECHNOLOGIES Centre's focus on holistic, enterprise-level services with outsourced IT capabilities enable the growth of recurring business with reduced customer turnover#143Financial Overview | Financial Snapshot 100.0% 46.2% growth since Transaction Date 123.4% II Transaction Date Revenue Growth (1) 2019 142.4% 2020 122.8% 2021 135.0% Organic Acquisitions Proforma Centre 2022 (1) Periods ended as of 12/31 except for TTM March; Proforma for 2022 acquisitions 146.2% TTM Mar-23 100.0% Transaction Date Adjusted EBITDA Growth (1) 69.3% growth since Transaction Date 133.9% 2019 Organic 123.0% 2020 112.7% 2021 156.3% Acquisitions Proforma Centre Centre TECHNOLOGIES 2022 I 169.3% TTM Mar-23#144Goals and Priorities | Current and Future 1 2 3 4 Grow revenue organically with focus on MRR Continually evolve and innovate product and service offerings Expand regionally in Texas and adjacent states Complete and integrate complementary add-on acquisitions Centre TECHNOLOGIES#145Financial Overview | Historical Timeline and Valuations (Equity Cost and FV $ in millions) $10.0 $8.0 $6.0 $4.0 $2.0 $0.0 $5.8 $5.8 Transaction Date $5.8 $5.8 January 2019 (A) 个 Dec-19 A - January 2019 Main Street and Chris Pace complete the minority recapitalization of Centre $5.8 Main Street Capital Corporation $6.2 Dec-20 Equity Cost ($) Adj. TTM EBITDA Growth % (from CIT/TSG Acquisition Date) $5.8 $6.2 Mar-21 $5.8 $5.8 $5.8 $5.8 Jun-21 Sep-21 wwww.Equity Fair Value ($) $5.8 $5.8 June - December 2021 (B) 个 Dec-21 Net Debt to Adj. TTM EBITDA as a % B-June - December 2021 Strategic initiatives implemented to accelerate the conversion from hardware/software sales to MRR $5.8 $5.8 NYSE: MAIN Mar-22 $6.9 Jun-22 March June 2022 (C) 个 $6.1 $8.2 C March - June 2022 Strategic initiatives begin to payoff as Centre's growth accelerates; Two acquisitions in 2Q22 expand Centre's geographical footprint $6.1 $8.7 DOOG MAIN ST Dec-22 CAPITAL CORPORATION $6.1 Sep-22 Adj. TTM EBITDA Growth % (from Transaction Date) $9.3 Mar-23 March 2023 (D) 个 500% 475% 450% 425% 400% 375% 350% 325% 300% 275% 250% 225% 200% 175% 150% 125% 100% 75% 50% 25% 0% -25% -50% D - March 2023 Centre is well positioned to continue growing with new and existing customers and expand its geographic reach mainstcapital.com#146Main Street Capital Corporation MAINST CAPITAL CORPORATION Future Outlook June 2023 NYSE: MAIN mainstcapital.com#147MAIN'S 5 Year Plan is the result of our annual strategic planning process between MAIN's executive management team and MAIN's Board of Directors 5 Year Strategic Overview - Investment Activity & Portfolio Growth Primary focus remains on growing our Lower Middle Market Portfolio Main Street Capital Corporation ● Continue to execute on MAIN's differentiated Lower Middle Market (LMM) strategy ● MAIN ST ● CAPITAL CORPORATION ● Continue to focus on growth of LMM investments LMM investments targeted to constitute greater than 50% of total investment portfolio (approximately 51% at March 31, 2023 at fair value) Continue to make meaningful equity investments in LMM companies (20% to 30% of capital invested in each new investment) Continued focus on opportunities to invest in existing portfolio companies (acquisitions and organic expansion) as part of value creation plans Maintain long-term to permanent holding period (developing "own forever companies"), resulting in a more diverse and higher quality investment portfolio Benefit from increased dividend income and NAV per share appreciation (from unrealized equity appreciation) as equity investments mature Continue to opportunistically recycle capital currently invested in specific companies where the existing investments and/or portfolio companies are not delivering on MAIN's key long-term value drivers Investments with limited dividend income on equity investments Investments with lack of visible opportunity for future equity value appreciation - Smaller legacy investments requiring disproportionate MAIN resources Increase LMM market penetration - significantly increase number of LMM investment professionals and investment teams, with total number of MAIN employees of approximately 150 by end of 2027 NYSE: MAIN mainstcapital.com#148Continued focus on Lower Middle Market investment strategy is complemented by increased growth of Asset Management Business, primarily fueled by Private Loan investment strategy 5 Year Strategic Overview - Investment Activity & Portfolio Growth (cont'd) Main Street Capital Corporation ● Continue growth of Asset Management Business (AMB) Goals and expectations for continued growth of AMB assets under management over near and long-term future MAINST ● CAPITAL CORPORATION • Focus on continued growth and best in class performance of MSC Income Fund (MSIF) and other existing AMB relationships - Key driver of ability to achieve expansion goals and expectations Other than MSIF, growth of AMB is expected to come almost exclusively from co-investment activities in MAIN's Private Loan strategy ● NYSE: MAIN Several potential avenues to achieve AMB growth and expansion - Additional private funds (consistent with MS Private Loan Fund I) - Expansion of Separately Managed Accounts business - Other investment vehicles prevalent in the BDC industry mainstcapital.com#149Maintain complementary benefits from Private Loan 5 Year Strategic Overview - Investment Activity & Portfolio Growth (cont'd) investment portfolio as a part of MAIN's growing investment portfolio Continued deemphasis of Middle Market investment portfolio Main Street Capital Corporation ● Continue growth in Private Loan (PL) portfolio Attractive due to significant involvement in /control over diligence, structuring and legal documentation during underwriting process and in post- investment activities; results in better net investment returns ● ● ● MAINST ● CAPITAL CORPORATION ● Continued expansion of PL investments led or co-led by MAIN; expected to grow as a percentage of overall PL across MAIN platform (MAIN portfolio and AMB clients) Continue rotation away from Middle Market (MM) debt investments to more attractive LMM and PL investment strategies PL investments targeted to constitute approximately 35% to 40% of MAIN's total investment portfolio (approximately 36% at March 31, 2023 at fair value) Utilize Private Loan strategy and MAIN capabilities to grow AMB Meaningful decrease in total dollar amount of MM investments, resulting in a larger decline of the MM portfolio as a percentage of MAIN's total investment portfolio as MAIN's overall investment portfolio continues to grow NYSE: MAIN MM investments targeted to constitute less than 5% of total investment portfolio (approximately 7% at March 31, 2023 at fair value) New investment activity on a very limited and opportunistic basis mainstcapital.com#1505 Year Strategic Overview - Capital Structure Maintain conservative leverage and low cost, diversified capital structure Main Street Capital Corporation ● Continue to diversify capital structure Utilize maximum permitted amount of attractive Small Business Investment Company (SBIC) debentures ($350 million) ● MAIN ST ● CAPITAL CORPORATION ● Long-term, low cost capital not subject to regulatory leverage limits Maintain investment grade debt ratings from Fitch and S&P and issue investment grade notes (with timing based upon market conditions) to maintain an attractive overall cost of capital, staggered debt maturities schedule and debt maturities that match profile of portfolio investments Maintain attractive revolving credit facilities to ensure adequate liquidity, provide short-term funding of portfolio investments and provide interim funding between long-term debt and equity capital activities Continue to operate with a conservative leverage profile Target Regulatory Debt to Equity, excluding SBIC debentures, of approximately 0.8x to 0.9x Continue effective use of low cost and efficient ATM equity offerings to maintain optimal liquidity, match capital with long term to permanent nature of LMM equity investments and maintain conservative leverage position Target Regulatory Asset Coverage Ratio between 2.25x to 2.1x, providing meaningful and conservative cushion to minimum BDC regulatory required ratio of 1.5x Maintain significant liquidity position at all times – liquidity is a significant strength at all times, but particularly during times of market stress or disruption (i.e. COVID-19 pandemic and banking industry disruptions) NYSE: MAIN mainstcapital.com#1515 Year Strategic Overview - Continued Income Growth Maintain growth in DNII per share through investment portfolio growth and leverage of efficient cost structure Main Street Capital Corporation MAIN ST Continue to grow Total Investment Income primarily through investment portfolio growth CAPITAL CORPORATION • Grow total investment income (at a minimum) in line with growth in total investment portfolio Supplement growth in Total Investment Income from investment portfolio with growth in Net Investment Income contribution from Asset Management Business (AMB) • Grow assets under management and recurring base fee income Continue receiving meaningful incentive fees ● Continue to leverage efficient internally managed cost structure to grow Distributable Net Investment Income (DNII) per share Maintain industry leading operating cost structure with operating expenses, excluding interest expense, as a percentage of total assets at or below 1.75% Maintain efficiency ratio of less than 22.5% The above ratios might increase slightly as growth of AMB is realized (since AMB will not grow MAIN's assets), but AMB should be meaningfully accretive to MAIN's DNII per share (no interest expense, investment capital or proportionate significant personnel increases) NYSE: MAIN Maintain strong total investment income to DNII conversion (i.e. operating margins) through efficient operating costs mainstcapital.com#152Main Street Capital Corporation 5 Year Strategic Overview - Continued Income Growth (continued) Maintain growth in DNII per share through investment portfolio growth and leverage of efficient cost structure MAIN ST ● CAPITAL CORPORATION Utilize MAIN's permanent capital base and unique tax structure for the benefit of MAIN's shareholders Maintain long-term to permanent holding period approach to MAIN's LMM investments Increased dividend income and unrealized appreciation - Increased portfolio diversity and overall higher quality portfolio NYSE: MAIN Retain and recycle capital from realized gains (as opposed to paying supplemental dividends) - More cost effective than equity offerings - Lower MAIN share count and higher earnings per share long-term mainstcapital.com#1535 Year Strategic Overview - Other Strategic Initiatives. Explore other strategic initiatives to enhance shareholder returns Main Street Capital Corporation ● Evaluate opportunities for growth through potential strategic mergers and acquisitions (M&A) activities Continue to be an active participant in BDC industry M&A opportunities - Could represent growth for MAIN's balance sheet and Asset Management Business (AMB) based upon nature of the opportunities Evaluate M&A opportunities that may also exist outside the BDC industry New investment capabilities for MAIN platform Other "strategic" investments in specialty finance Evaluate other capabilities to assist with growth of AMB ● MAIN ST ● CAPITAL CORPORATION Evaluate other opportunities for growth in AMB "Acqui-hires" of new investment skillsets and capabilities Add new non-investment skillsets and capabilities to increase ramp of AMB NYSE: MAIN mainstcapital.com#1545 Year Strategic Overview - Shareholder Dividends Goal is to provide meaningful annual growth of MAIN's Monthly Dividends Supplemental Dividends provide the opportunity for additional shareholder returns MAIN plans to retain future realized gains for reinvestment Main Street Capital Corporation ● Long-term plan includes growth of Monthly Dividends and variable quarterly Supplemental Dividends based upon actual DNII per share ● MAIN ST ● CAPITAL CORPORATION ● Goal to provide higher growth rates for Monthly Dividends in forward five years We expect to recommend that our Board declare future Supplemental Dividends only to the extent Distributable Net Investment Income (DNII) significantly exceeds monthly dividends paid in future quarters Supplement Dividends will be variable based upon actual DNII growth and results, with goal to provide additional current return to MAIN shareholders Current performance and near-term expectations should result in meaningful recurring supplemental dividends for the next few quarters Supplemental Dividends, if any, will be at a discount to actual excess earnings (DNII in excess of monthly dividends) Any Supplement Dividends will also be in arrears on a quarterly basis, providing additional flexibility Current and long-term plan is to retain capital from realized gains on our equity investments for future reinvestment purposes (as opposed to paying these realized gains out as supplemental dividends) as another tool to maintain conservative leverage NYSE: MAIN mainstcapital.com#155Successful strategy execution should result in continued superior returns for MAIN shareholders 5 Year Strategic Overview - Maintain Superior Shareholder Returns Main Street Capital Corporation ● Differentiated strategy will maintain superior shareholder returns ● ● MAINST ● CAPITAL CORPORATION Maintain long-term mid-teens Return on Equity over five year period (with annual fluctuations based upon market conditions) Stock price appreciation through continued growth in monthly dividends, with significant DNII coverage of monthly dividends, and increases in NAV per share Target total annual return to shareholders of 12.5% to 15% annually Consistent with historical returns, we believe these results would compare very favorably to other yield-oriented investment options and to other publicly traded companies generally NYSE: MAIN Asset Management Business and other strategic initiatives (if opportunities arise) provide opportunity for additional returns to shareholders mainstcapital.com