#1NiSource Ⓡ We exist to deliver safe, reliable energy that drives value to our customers Sale of a 19.9% Ownership Interest in NIPSCO $2.40B Equity Capital Raise to Drive Sustainable Growth Across NiSource, a Premium Utility June 20, 2023#2FORWARD-LOOKING STATEMENTS This presentation contains "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, as amended (the "Securities Act"), and Section 21E of the Securities Exchange Act of 1934, as amended (the "Exchange Act"). Forward-looking statements in this presentation include any statements regarding the ability to complete the Transaction on the anticipated timeline or at all; the anticipated benefits of the Transaction if completed; the projected impact of the Transactions on our performance or opportunities; any statements regarding our expectations, beliefs, plans, objectives or prospects or future performance or financial condition as a result of or in connection with the Transaction; statements concerning our plans, strategies, objectives, expected performance, expenditures, recovery of expenditures through rates, stated on either a consolidated or segment basis; and any and all underlying assumptions and other statements that are other than statements of historical fact. Investors and prospective investors should understand that many factors govern whether any forward-looking statement contained herein will be or can be realized. Any one of those factors could cause actual results to differ materially from those projected. Expressions of future goals and expectations and similar expressions, including "may," "will," "should," "could," "would," "aims," "seeks," "expects," "plans," "anticipates," "intends," "believes," "estimates," "predicts," "potential," "targets," "forecast," and "continue," reflecting something other than historical fact are intended to identify forward-looking statements. All forward-looking statements are based on assumptions that management believes to be reasonable; however, there can be no assurance that actual results will not differ materially. Factors that could cause actual results to differ materially from the projections, forecasts, estimates and expectations discussed in this presentation include, among other things, risks and uncertainties relating to the timing and certainty of closing the Transaction; the ability to satisfy the conditions to closing the Transaction, including the ability to obtain FERC approval necessary to complete the Transaction; the ability to achieve the anticipated benefits of the Transaction; the effect of this communication on our stock price; the effects of transaction costs; the effects of the Transaction on industry, market, economic, political or regulatory conditions outside of our control; any disruption to our business from the Transaction, including the diversion of management time on Transaction-related issues, our ability to execute our business plan or growth strategy, including utility infrastructure investments; potential incidents and other operating risks associated with our business; our ability to adapt to, and manage costs related to, advances in technology; impacts related to our aging infrastructure; our ability to obtain sufficient insurance coverage and whether such coverage will protect us against significant losses; the success of our electric generation strategy; construction risks and natural gas costs and supply risks; fluctuations in demand from residential and commercial customers; fluctuations in the price of energy commodities and related transportation costs or an inability to obtain an adequate, reliable and cost-effective fuel supply to meet customer demands; the attraction and retention of a qualified, diverse workforce and ability to maintain good labor relations; our ability to manage new initiatives and organizational changes; the actions of activist stockholders; the performance of third-party suppliers and service providers; potential cybersecurity attacks; increased requirements and costs related to cybersecurity; any damage to our reputation; any remaining liabilities or impact related to the sale of the Massachusetts Business; the impacts of natural disasters, potential terrorist attacks or other catastrophic events; the physical impacts of climate change and the transition to a lower carbon future; our ability to manage the financial and operational risks related to achieving our carbon emission reduction goals, including our Net-Zero Goal; our debt obligations; any changes to our credit rating or the credit rating of certain of our subsidiaries; any adverse effects related to our equity units; adverse economic and capital market conditions or increases in interest rates; inflation; recessions; economic regulation and the impact of regulatory rate reviews; our ability to obtain expected financial or regulatory outcomes; continuing and potential future impacts from the COVID-19 pandemic; economic conditions in certain industries; the reliability of customers and suppliers to fulfill their payment and contractual obligations; the ability of our subsidiaries to generate cash; pension funding obligations; potential impairments of goodwill; the outcome of legal and regulatory proceedings, investigations, incidents, claims and litigation; potential remaining liabilities related to the Greater Lawrence Incident; compliance with the agreements entered into with the U.S. Attorney's Office to settle the U.S. Attorney's Office's investigation relating to the Greater Lawrence Incident; compliance with applicable laws, regulations and tariffs; compliance with environmental laws and the costs of associated liabilities; changes in taxation; other matters in the "Risk Factors" section and the "Management's Discussion and Analysis of Financial Condition and Results of Operations" section of our Annual Report on Form 10-K for the fiscal year ended December 31, 2022 and the "Risk Factors" section of our Quarterly Report on Form 10-Q for the first quarter of 2023, some of which risks are beyond our control. All forward-looking statements are expressly qualified in their entirety by the foregoing cautionary statements. We undertake no obligation to, and expressly disclaim any such obligation to, update or revise any forward-looking statements to reflect changed assumptions, the occurrence of anticipated or unanticipated events or changes to the future results over time or otherwise, except as required by law. Regulation G Disclosure Statement This presentation includes financial results and guidance for NiSource with respect to net operating earnings available to common shareholders, diluted earnings per share, and funds from operations/debt, which are non-GAAP financial measures as defined by the SEC's Regulation G. The company includes these measures because management believes they permit investors to view the company's performance using the same tools that management uses and to better evaluate the company's ongoing business performance. With respect to such guidance, it should be noted that there will likely be a difference between these measures and their GAAP equivalents due to various factors, including, but not limited to, fluctuations in weather, the impact of asset sales and impairments, and other unusual or infrequent items included in GAAP results. The company is not able to estimate the impact of such factors on their GAAP equivalents and, as such, is not providing such guidance on a GAAP basis. In addition, the company is not able to provide a reconciliation of its non-GAAP net operating earning's guidance or its funds from operations/debt guidance to their GAAP equivalent without unreasonable efforts. We exist to deliver safe, reliable energy that drives value to our customers NiSource | NYSE: NI| nisource.com | om 2#3ENHANCED NISOURCE VALUE PROPOSITION DRIVING SUSTAINABLE GROWTH $30B Planned Long-Term Infrastructure Investments over the next 10 years Net Zero By 2040² Driving Toward 14% -16% Long-term FFO/ Debt Target 90% Reduction in GHG Emissions by 2030 100% Regulated Across Six Constructive Jurisdictions 6% -8% Expected Annual NOEPS¹ Growth Through 2027 8% -10% Expected Annual Utility Rate Base Growth Significant Investment Opportunities 60% -70% Targeted Annual Dividend Payout Ratio 9%-11% Expected Annual Flat O&M Total Shareholder Return Operational excellence drives affordability FINANCIAL FOUNDATION Efficient Recovery Mechanisms We exist to deliver safe, reliable energy that drives value to our customers NiSource | NYSE: NI| nisource.com | ♥M ~$16.6B Regulated Electric and Gas Rate Base 3 Strengthened Balance Sheet 1 Net Operating Earnings Per Diluted Share (Non-GAAP) Goal for Scope 1 and 2 emissions 2 3 Estimated total shareholder return at a constant P/E ratio 3#4BUILDING ON OUR TRACK RECORD OF EXECUTION AND GROWTH NOEPS* (GROWTH) DIVIDEND (ANNUAL GROWTH) CREDIT (FFO/DEBT) REGULATORY EXECUTION OPERATIONAL EXCELLENCE (SAFETY, O&M MANAGEMEMENT, ETC.) 2021 $1.37 $0.88 -13.5% We exist to deliver safe, reliable NiSource | NYSE: NI| nisource.com | ♥M 2022 energy $1.47 (+7.3%) $0.94 (+6.8%) -13.5% 2023 $1.54-$1.60 $1.00 (+6.4%) Execute Minority Interest Sale NIPSCO Electric Rate Case Tracking Mechanisms 2024 2025 that drives value to our customers 2026 Deliver 6-8% Annual NOEPS GROWTH 2027 9-11% Total Shareholder Return 60-70% PAYOUT Strengthened Balance Sheet to Achieve 14-16% FFO/DEBT Continuing to Prioritize Safety while Optimizing our Long-Term Cost Profile * Diluted Net Operating Earnings Per Share (Non-GAAP). For the GAAP Diluted Earnings Per Share and the reconciliation of GAAP to non-GAAP diluted earnings per share, see Schedule 1 in the appendix to NiSource's 1Q 2023 Results presentation Sustained Superior Regulatory Execution PROGRESS On track - Solid 1Q Results On track On track - Minority Interest Sale Announced On track - Filed Electric Rate Case Settlement On track 4#5$2.40B MINORITY INTEREST SALE AND EQUITY CAPITAL RAISE AT NIPSCO Blackstone to acquire a 19.9% interest in NIPSCO for $2.15B, and is committed to funding its pro rata share of ongoing capital requirements, which is supported by a $250M equity commitment letter ● ● Highly attractive and efficient equity financing $2.40B capital infusion to support NiSource and its fastest growing utility, including to fund ongoing capital needs associated with the renewable generation transition underway Highlights NIPSCO's industry-leading value proposition Multi-decade rate base investment opportunity driven by decarbonization, electrification, electric and gas system reliability, and customer growth leads to ~$2.1B expected 2023E CapEx opportunity and long-term 13-14% rate base growth CAGR at NIPSCO Efficient rate structure that drives predictable cash flow and returns Operates in Indiana, one of the most constructive utility jurisdictions in the U.S., with strong support for utility-owned generation and affordable energy Economically robust service territory benefitting from on-shoring and migration trends, as well as robust economic development - $2.15B upfront cash payment for the 19.9% interest implies an equity value of $10.8B and an enterprise value of $14.3B¹ for 100% of NIPSCO 32.5x LTM P/E and 1.85x EV / YE 2022 Rate Base multiples¹ for the 19.9% interest represent a significant premium to precedent transactions Inclusion of Blackstone's $250M additional investment commitment increases the total capital raise to $2.40B This capital is being raised at a substantial premium to alternative sources of financing Establishes a long-term partnership with Blackstone, a leading global infrastructure investor With $36B in assets under management, Blackstone is among the largest infrastructure investors globally, with a permanent capital approach to investing in high quality, stable, cash generative, long duration assets Blackstone is aligned with NIPSCO in its commitment to invest in Indiana and into energy transition as a long-term partner to NiSource Significant expected go-forward benefits to both NiSource and NIPSCO Outcome consistent with previous NiSource commitments, and demonstrates ongoing best-in-class execution capabilities Reaffirming 2023 Non-GAAP NOEPS guidance of $1.54 to $1.60 Maintaining long-term annual NOEPS growth guidance of 6-8% and FFO/Debt target of 14-16% - Transaction Supports NiSource's Robust Capital Plan While Strengthening the Balance Sheet ¹ Figures based on $3.5B NIPSCO net debt (excludes NiSource holding company debt) and $333M NIPSCO LTM Non-GAAP Net Income as of 31-Mar-2023, and $7.7B YE 2022 Rate Base. We exist to deliver safe, reliable energy that drives value to our customers NiSource | NYSE: NI| nisource.com | om 5#6TRANSACTION SUMMARY Topic Minority Investor Purchase Price Structure Governance Operations Customers Use of Proceeds Closing Conditions Timing Description Blackstone Infrastructure Partners, a permanent capital investor across global infrastructure asset classes Commitment to fund $2.40B through our five-year plan $2.15B cash investment at closing in exchange for a 19.9% interest in NIPSCO Commitment to fund pro rata share of NIPSCO's ongoing capital requirements, supported by a $250M equity commitment letter NiSource to retain control with 80.1% ownership in NIPSCO Tax-efficient transaction that utilizes a partnership structure for tax purposes Blackstone will receive minority rights commensurate with a 19.9% interest NiSource will remain the sole operator of NIPSCO ■ No impact to NIPSCO employees or management team Upholds NIPSCO's century-long commitment to delivering reliable and affordable energy to Northern Indiana Funding NIPSCO capital needs, providing increased surety in NIPSCO's ability to finance its energy transition strategy Strengthening NiSource's balance sheet and other corporate uses in line with NiSource's capital allocation objectives ■FERC approval Expected transaction close by year-end 2023 We exist to deliver safe, reliable energy that drives value to our customers NiSource | NYSE: NI| nisource.com | om 6#7PREMIUM VALUATION HIGHLIGHTS THE VALUE EMBEDDED IN NISOURCE $2.40B Equity Raise at a Premium Valuation 18.4 x NiSource² P/E Multiple¹ -77% premium 32.5 X Transaction Substantial premium to NiSource's P/E and to alternative sources of financing NIPSCO Benefits from NiSource's Full Operating Platform ■ Shared services across 4M customers delivering greater customer value Enhanced purchasing power fueled by a robust capital plan across six operating companies Benefitting from energy diversification, particularly through the energy transition ■ Regulatory diversification to support and grow safety and reliability initiatives for our communities Highlights Immense Value Embedded in NiSource Columbia Gas 59% $ 11.3B We exist to deliver safe, reliable energy that drives value to our customers NiSource | NYSE: NI| nisource.com | ♥M Equity Value NiSource Market Capitalization² LTM Operating Earnings¹ $ 10.8B NIPSCO Contribution to NiSource NIPSCO 41% Implied Value for 100% of NIPSCO³ Columbia Gas 53% 2022 Rate Base Implied value for 100% of NIPSCO represents -96% of NiSource market capitalization, despite NIPSCO contributing <50% to consolidated earnings and rate base NIPSCO 47% ¹LTM P/E multiple and earnings based on the LTM ended 31-Mar-2023. Transaction multiple shown reflects $2.15B investment at closing. 2 Market data as of 16-Jun-2023.3 Value for NIPSCO implied by upfront consideration of $2.15B in exchange for 19.9% ownership of NIPSCO. 7#8EXCEPTIONAL OUTCOME ACHIEVES ALL OF NISOURCE'S OBJECTIVES Transaction Objectives Strengthen balance sheet and financial flexibility Raise capital at highly attractive, premium valuation Reduce reliance on capital markets and minimize equity needs Retain NiSource's benefits of scale and regulatory diversification Preserve NIPSCO's access to NiSource's shared service model ■ Supports capital investment execution and energy transition Introduce a stakeholder to support economic development in Indiana Highlight the value of NIPSCO embedded within NiSource Objectives Accomplished We exist to deliver safe, reliable energy that drives value to our customers NiSource | NYSE: NI| nisource.com | om 14-16% FFO/debt $2.40B equity raise at a 77% premium to NiSource's P/E Significantly reduces NiSource's equity needs 4M customer platform across six states supports the shared service model, keeping customer value in focus Enhances execution of robust capital plan and ability to deliver safe and reliable energy service Permanent capital partner that will provide ongoing capital to NIPSCO, supported by $250M equity commitment letter Blackstone will help NiSource to identify and implement economic development opportunities Implied value for 100% of NIPSCO is 96% of NI market capitalization, vs. <50% contribution to consolidated earnings and rate base Highly successful outcome, despite the challenging market backdrop, reinforces NiSource's best-in-class execution capabilities 8