#1INVESTOR PRESENTATION QUARTER ENDED MARCH 31, 2023 SELECTIVE INSURANCE® 9 Z S + C é 13 5 9 m F f 5 1 G レ I 8 ~ O 7 8 O NO 6 * INTERIOR DESIGN SOLUTION ARCHITECTURE X & START-UP LEAR#2Safe Harbor Statement We make certain statements and reference other information in this presentation that are "forward-looking statements” as defined in the Private Securities Litigation Reform Act of 1995 ("PSLRA"). The PSLRA provides a safe harbor under the Securities Act of 1933 and the Securities Exchange Act of 1934, as amended, for forward-looking statements relating to our intentions, beliefs, projections, estimations, and forecasts of future events or our future financial performance. Forward-looking statements involve known and unknown risks, uncertainties, and other factors that may cause actual results to differ materially. We can give no assurance that our expectations expressed in forward- looking statements ultimately will be correct. We discuss factors that could cause our actual results to differ materially from those we project, forecast, or estimate in forward-looking statements in further detail in Selective's public filings with the United States Securities and Exchange Commission. We undertake no obligation to publicly update or revise any forward-looking statements - whether as a result of new information, future events or otherwise - other than as the federal securities laws may require. This presentation also includes certain non-GAAP financial measures within the meaning of Regulation G, including "non-GAAP operating earnings per share," "non-GAAP operating income," and "non-GAAP operating return on equity." Definitions of these non-GAAP measures and a reconciliation to the most comparable GAAP figures are available in our Annual Report on Form 10-K and our Supplemental Investor Package, both found on our website <www.selective.com> under "Investors/Reports & Earnings/Presentations." We believe investors and other interested persons find these measurements helpful, as they provide a consistent basis for comparing our results between quarters and with our industry competitors. These non-GAAP measures, however, may not be comparable to similarly titled measures used outside of the insurance industry. Investors are cautioned not to unduly rely on these non-GAAP measures in assessing our overall financial performance. SELECTIVE INSURANCE® 2#3SELECTIVE INSURANCE® Overview 3#4SELECTIVE INSURANCE® A Track Record of Superior Execution Nine Consecutive Years of Double-Digit Non-GAAP Operating ROEs* and Above Average Industry Growth 2022 Non-GAAP Operating ROE of 12.4%* nn $6.2B Market Cap (as of 6/7/2023) 95+ Years of Financial Strength and Superior Execution $3.6B 2022 NPW (up 12% Y/Y) × 95.1% % 2022 GAAP Combined Ratio *For further information on non-GAAP financial measures, please see "Safe Harbor Statement" on Page 2. 4#5SELECTIVE INSURANCE® · • Our Sustainable Competitive Advantages Competitive Position Enhanced by Working Towards the Benefit of all our Stakeholders AGENCY 皿 Distribution model emphasizes franchise value with high-quality partners Appointment of high-quality independent agent distribution partners with whom we have close relationships Enables effective management of pricing and retention Presents significant opportunity for profitable growth Unique locally based field model Locally based underwriting, claims, and safety management specialists Claims specialists regionally organized by specialty 0000 Sophisticated tools for risk selection, pricing, and claims management Our proven ability to develop and integrate these tools gives us confidence that we can effectively manage profitability in a more uncertain loss trend environment Highly engaged and aligned talent across the organization @ Superior omni-channel customer experience delivered by best-in-class employees • • Strong focus on customer experience Developing holistic solutions for 24-hour omni-channel shared experience • Increased customer engagement • Value-added services 5#6Super Regional with National Capabilities Standard Commercial (81% of NPW) Standard Personal (9% of NPW) Excess & Surplus (10% of NPW) 30 States & D.C. Focus on maintaining growth and profitability targets in a more uncertain loss trend environment SELECTIVE INSURANCE® 15 States 50 States & D.C. Shifted focus to "mass- affluent" market; price increases expected to accelerate in latter half of 2023 Strong growth and profitability; market dynamics remain supportive#7Well-positioned for Continued Outperformance SELECTIVE INSURANCE® Topline/ Underwriting Ongoing successful execution of 3% market share strategies and geo-expansion Strong NPW growth from rising prices, increased exposure, solid retention rates, and new business volumes • Combined ratio guidance* of 96.5% for 2023; long-term 95% target ↑ . . Pricing/ Loss Trends Decade-long track record of pursuing price increases. in line with projected loss trend Continued loss trend uncertainty; projected commercial lines loss trend of 6.5%, with property lines at 7% and casualty lines at 6% Commercial lines pricing environment remains rational, particularly in property lines ↑ • Investments Prudently managed the investment portfolio to optimize risk/return in a rising interest rate environment Significant increase in book yield and credit quality; investment income projected to grow ~30% in 2023 Investment leverage of 3.4x enables strong ROE contribution ↑ Balance Sheet/ Risk Management Strong financial position - solid balance sheet, prudent reserving, and holding company liquidity well above targets Strong underwriting controls and exposure management to limit CAT loss volatility Increased reinsurance retentions at 1/1/23, while maintaining conservative program and increasing top layer limit ↑ *as of May 4, 2023 7#8[ Our Key Accomplishments Underwriting Discipline Continuing our decade-long track record of effectively managing commercial lines pricing and retention rates in a dynamic loss trend environment Strong Top-Line Growth Leveraging our unique field underwriting model In 2022 000 and sophisticated tools and technology to generate profitable growth SELECTIVE INSURANCE® AGENCY D Geographic Expansion Expanded our Commercial Lines footprint into Vermont, Idaho, and Alabama in 2022, with Maine and West Virginia targeted for early 2024 New Automation Platforms Our new Small Business and E&S automation platforms dramatically enhance ease-of-use for our distribution partners New Agency Appointments We appointed 118 new agencies, bringing our total to approximately 1,500 agencies with 2,600 storefronts 8#9Strong ROE Outperformance Relative to Peers SELECTIVE INSURANCE® 15% 10% 5% 10.3% 8.6% Historical Non-GAAP Operating ROES* SIGI Peer Avg. Elevated CAT losses 14.6% 12.4% 8.7% 8.0% 0% 2014 2015 2016 2017 Peer index includes TRV, HIG, CNA, CINF, THG, and UFCS 2018 2019 2020 2021 2022 1Q23 *For further information on non-GAAP financial measures, please see "Safe Harbor Statement" on Page 2. • 12.4% non-GAAP operating ROE* in 2022 and 14.6% in 1Q23 driven by: - - - Solid underwriting profitability Manageable CAT losses Strong investment contribution Track record of generating ROES well in excess of our cost of capital and peer group averages Nine consecutive years of double-digit non-GAAP operating ROES* averaging 11.9% between 2014 and 2022 9#10Excellent Historical Operating Results Historical GAAP Combined Ratios 2022 Highlights SELECTIVE INSURANCE® 100% 95.8% 95% 95.2% COVID-19 and elevated catastrophes 90% -Underlying Combined Ratio** 85% -Reported Combined Ratio - GAAP combined ratio of 95.1% - NPW growth of 12% 96.5% - 95.1% 93.3% 92.0%* 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023F *2023F combined ratio estimate is ex-cat and assumes no additional prior year casualty reserve development ** Underlying GAAP combined ratio excludes catastrophe losses and prior year casualty reserve development • After-tax net investment income of $232 million 2023 Guidance¹ - GAAP combined ratio of 96.5% includes net catastrophe losses of 4.5 points and assumes no additional prior year casualty reserve development - $300 million of after-tax net investment income, including $30 million from alternative investments 21% overall effective tax rate 61 million weighted average shares ¹as of May 4, 2023 10#11SELECTIVE INSURANCE® Our Strategic Initiatives 11#12Our Major Strategic Initiatives SELECTIVE INSURANCE® 000 0 000 ° 00 • 000 0000 Leverage Sophisticated Tools to Achieve Adequate Pricing Deploy sophisticated underwriting and pricing tools to improve risk selection and achieve price increases ≥ loss trends Continued Profitable Growth Expanding "share of wallet" and new agent appointments; geo-expansion D Excellent Customer Service ooo Continue to deliver superior omni-channel customer experience Culture Focused On Innovation and Sustainability A culture of innovation and sustainability centered around diversity, equity, and inclusion 12#13Renewal Pure Price (%) SELECTIVE INSURANCE® Consistently Achieving Price Increases In Alignment with Loss Trend Commercial Lines Pricing and Retention SIGI Pricing ICLIPS Pricing -SIGI Retention 88% 10.0% 6.0% 2.0% -2.0% 2009 2011 2013 2015 2017 2019 2021 84% 80% 76% 1Q23 CLIPS: Willis Towers Watson Commercial Lines Insurance Pricing Survey; 1Q23 CLIPS pricing is not yet available Retention (%) . Selective's renewal pure price increases exceeded industry average from 2009-2018 • Attractively priced book with strong embedded profitability • Ability to obtain appropriate price enabled by: - ― Strong distribution partner relationships Sophisticated tools and actionable data Culture of underwriting discipline Commercial Lines renewal pure price increases averaged 7.0% in 1Q23; up from 5.6% in 4Q22 13#14Portfolio Approach to Pricing and Underwriting Helps Drive Business Mix Improvements Commercial Lines Pricing by Retention Group SELECTIVE INSURANCE® 14% 812% Renewal Pure Price 10% 8% 6% 4% Pure Rate % Premium Renewed 95% 85% 75% 2% 0% 65% Excellent Above Average Average Below Average Low & Very Low Point of Renewal Retention 16% 15% 44% 17% 8% % of Premium As of March 31, 2023 May not foot due to rounding. Portfolio management approach yields higher retention and rate • Account-specific pricing, including: Predictive modeling Relative loss frequency and severity Pricing deviation - Hazard and segment consideration Strong focus on developing tools and technologies that enable more effective decision making 14#15Targeting Profitable Growth Over Time Delivered an 8% NPW compounded annual growth rate over the last nine years Commercial Lines Pricing by Retention Group Managed Premium Volume During Soft Market $ 3.6B Lower Risk 2020 2022 SELECTIVE INSURANCE® Commercial Lines Growth Drivers Target of growing "share of wallet" to 12% with existing distribution partners Target of appointments to represent 25% share in existing markets Geo-expansion New products Additional NPW opportunity of about $3B by achieving a 3% commercial lines market share in existing footprint Higher Risk M&A 15#16Greenfield Geo-Expansion Enhances Growth Opportunities Diversification and spread of risk, with a target of having national capabilities Recent Timeline of our Disciplined Approach to Geo-Expansion SELECTIVE INSURANCE® Footprint States Target Expansion States for 2024* 2017-2018 - - Established new Southwest regional hub by entering AZ, CO, NM, and UT for Commercial Lines NH for Commercial Lines AZ and UT for Personal Lines 2022 - Expanded into VT in June 2022 Expanded into AL and ID in October 2022 Early 2024 Target - West Virginia and Maine* 16 *Subject to regulatory approval#17Focus on Customer Experience to Drive Retention Customer-centricity is core to who we are as a company Advancing Value-Added Services ☹ Actionable Insights Maximizing Digital Utilization Delivering services that help our insureds mitigate risk differentiates us in the market Developing a "360-degree" view of the customer; partnering with agents to provide a seamless customer experience Providing an omni-channel customer experience in a 24/7 environment through customized proactive messaging for product recalls, notices of loss, and policy changes SELECTIVE INSURANCE® 17#18SELECTIVE INSURANCE® A Culture of Strong Governance and Transparency Sustainability Committee overseen by senior management Diverse, engaged Board with strong oversight of key risk areas Having a Positive Impact on our Communities and Society Safety Management services make our insureds and communities safer The Selective Insurance Group Foundation makes philanthropic investments that strengthen our communities A Understanding and Attempting to Mitigate Climate Change Risk Diverse, engaged Board with strong oversight of key risk areas Publication of our inaugural TCFD report Developing Leadership in Sustainability and Corporate Social Responsibility Providing Customers with Responsive Claims Services and Risk Mitigation Solutions Responsive claims service Seamless omni-channel customer experience Value-added tools and technologies to help mitigate customer risk Building a Highly Engaged Team of Employees and Leaders Strong focus on attracting, retaining, and promoting the best talent Emphasis on workplace flexibility Significant initiatives to advance DE&I 18#19SELECTIVE INSURANCE® Financial Overview 4 19#20Lower Risk Profile and Strong Financial Strength Conservative business and balance sheet profile allows higher operating leverage Low to Medium Hazard Writer Prudent Reinsurance Program SELECTIVE INSURANCE® A LOWER RISK PROFILE $ es ( RATINGS AM Best: A+ Conservative Investment Fitch: A+ Portfolio Disciplined Reserving Processes S&P: A Moody's: A2 20#21A Writer of Predominantly Low-To Medium-Hazard Risks Percent of Policies with TIV¹ or Property Casualty Limits of $1M or Less Notes: Standard Commercial Lines 76% 86%* ** Standard Personal Lines 76% 96% E&S Lines 96% 99% Figures as of December 31, 2022 1TIV refers to total insured value ** Excludes workers compensation policies, which do not have statutory policy limits SELECTIVE INSURANCE® • • Manage volatility of underwriting results, in part through maintaining a smaller limit profile Low account sizes (premium per policyholder) averaging: - $15.3K for Standard Commercial $2.6K for Standard Personal • - $3.8K for E&S Low reinsurance attachment points for property (per risk) and casualty (per occurrence) A low volatility portfolio of risks 21 21#22* Conservative Investment Portfolio Investment Portfolio at 3/31/23 Fixed Income 88% Short-Term 4% Equities* 2% | Alternatives & Other 6% $ $8.0B of Investments SELECTIVE INSURANCE® Core fixed income and short-term investments comprised 93% of investment portfolio at 3/31/23 - "AA-" average credit quality - Effective duration of 4.1 years • Risk asset allocation (high yield, public equity, and alternatives) at 9.9% of invested assets Ongoing diversification of our alternative. investments portfolio by strategy and vintage Equities consist of publicly traded fixed income, exchange-traded funds, business development companies (BDCs), and interval funds Conservative investment management philosophy, with a focus on highly rated fixed income securities 22 22#23Active Portfolio Management Drives Investment Results SELECTIVE INSURANCE® 4.0% 3.0% Historical After-Tax Fixed Income Portfolio Yields 2.2% 2.1% 2.0% 1.9% 1.9% 2.9% 2.8% 2.6% 2.6% 3.1% 3.8% 1.0% 2014 2015 2016 2017 2018 2019 2020 2021 2022 1Q23 Higher interest rates had helped new money reinvestment rates - $2.7B of new money invested in 2022 and $1.1B in 1Q23 Pre-tax book yield on fixed income portfolio up ~137 basis points since 12/31/2021 Every 100 basis points of incremental pre-tax investment return translates to ~260 basis points of additional ROE After-tax yield on our fixed income portfolio was 3.1% in 2022 and 3.8% in 1Q23 23#24SELECTIVE INSURANCE® Historical Catastrophe Loss Impact Below Industry Average Impact of Catastrophe Losses on Combined Ratio 12 6 0 Elevated frequency of CAT losses кий 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 Note: Catastrophe impact for P&C industry based on AM Best estimates P&C Industry SIGI Catastrophe loss impact over the past 20 years has averaged - - - 5.5 percentage points for the P&C industry 3.5 percentage points for Selective Catastrophe loss mitigation initiatives include: Strict guidelines for coastal properties Focus on geographic diversification and growth that minimizes peak catastrophe aggregations - Conservative reinsurance program Relatively low historical combined ratio volatility from catastrophe losses 24 24#25Conservative Reinsurance Program SELECTIVE INSURANCE® 40% Net Single-Event Hurricane Loss* as a % of Equity 30% 20% 10% * 7% 5% 4% 3% 3% 2% 0% 25 50 100 150 21% 200 250 500 (Return Period in Years) Single event hurricane losses are net of reinsurance, after tax, and reinstatement premiums as of 1/1/23. GAAP equity as of 12/31/22. • 2023 property catastrophe treaty structure Coverage of $915M in excess of $60M retention, with net purchased limits totaling $810M $216M in collateralized limit, primarily in the top layer of the program Property XOL treaty covers losses up to $67M in excess of $3M retention on a per risk basis Casualty XOL treaty covers losses up to $88M in excess of $2M retention on a per occurrence basis Balance sheet protection through conservative program and strong panel of reinsurance partners 25#26-4.0% 2006 2007 2008 2009 2010 2011 2012 2013 Strong Reserving Track Record Impact of Casualty Reserve Development on our Combined Ratio 0.0% -2.0% Disciplined reserving practices - Quarterly actuarial reserve reviews. Semi-annual independent review Independent year-end opinion Favorable reserve development in Workers Compensation, General Liability, BOP, and Bonds in 2022; partially offset by adverse trends in Commercial Auto 2014 2015 2016 2017 2018 2019 2020 2021 2022 1Q23 Seventeen consecutive years of net favorable casualty reserve development 26 SELECTIVE INSURANCE®#27Strong Capital and Liquidity Position, Greater Expense Focus Capital and Liquidity Plan • Debt-to-capital ratio of 15.9% NPW-to-surplus ratio of ~1.46x is in the • . middle of our target range of 1.35x - 1.55x Parent company cash and investments totaling $497M is in excess of our target of 2x annual recurring outflow Instituted opportunistic $100M share repurchase authorization in 2020; $84.2M remained as of 3/31/23 • Investing in the business currently provides the most attractive capital deployment opportunities SELECTIVE INSURANCE® • Expense Management Expecting expense ratio pressure in 2023 due to higher reinsurance costs; targeting improvement over the next few years Areas for operational enhancements include: - Workflow and process improvements Robotics and artificial intelligence Talent development Product innovation Note: Financial statistics are as of March 31, 2023 27#28Focus on ROE and Growth in Book Value Per Share* SELECTIVE INSURANCE® Strong Track Record of Book Value per Share Growth and Shareholder Value Creation Over Time $50 $40 $30 $20 $10 $0 2010 2016 2015 2014 2013 2012 2011 IGAAP Stockholders' Equity 2019 2018 2017 ($ in millions) $3,000 $2,500 $2,000 $1,500 $1,000 $500 $0 Book Value Per Share Generating non-GAAP operating ROE** in line with our long-term target Superior growth in book value per share Expected higher total shareholder returns over time *Book value per share decreased 17% for 2022 compared to 2021 primarily due to increased net unrealized losses. Adjusted book value per share increased 5% for 2022 compared to 2021. **Refer to "Safe Harbor Statement" on page 2 of this presentation for further detail regarding certain non-GAAP financial measures 28#29Total Shareholder Returns Have Outperformed Benchmarks Over Longer Term Total Shareholder Return • SIGI ■S&P Prop/Cas S&P 500 20% 16.6% 15% 10.9% 11.2% 11.6% 12.2% 9.2% • 10% 7.9% 7.5% 8.1% 5% 0% -1.0% -5% -3.9% -10% 1Q23 -7.7% 1 YEAR 5 YEARS Note: Total shareholder return calculations for 1, 5, and 10 years are as of March 31, 2023 SELECTIVE INSURANCE® 10 YEARS Solid long-term outperformance in TSR relative to S&P P&C insurance and S&P 500 indices Common stock price performance has reflected our ability to generate strong and consistent financial results Our common stock has performed well against peers and equity markets recently, and over the past 5- and 10-year periods 29#30Leveraging our competitive strengths to generate sustained financial outperformance A distribution model that emphasizes franchise value: We appoint and having meaningful, close business relationships with high-quality, independent distribution partners, who value us and our business model, and provide us opportunities to grow profitably with them Unique field model enabled by sophisticated technology Strong customer experience Our Value Proposition Excellent growth opportunities within footprint and through geo-expansion Solid underwriting margins and non-GAAP operating ROES* in line with our financial targets Conservative approach to risk selection and balance sheet management SELECTIVE INSURANCE® *For further information on non-GAAP financial measures, please see "Safe Harbor Statement" on Page 2. 30#31INVESTOR PRESENTATION QUARTER ENDED MARCH 31, 2023 SELECTIVE INSURANCE® 9 Z S + C é 13 5 9 m F f 5 1 G レ I 8 ~ O 7 8 O NO 6 * INTERIOR DESIGN SOLUTION ARCHITECTURE X & START-UP LEAR