SELECTIVE INSURANCE GROUP INC

Insurance Operations

The following table provides quantitative information for analyzing the combined ratio:

Lower NPWin Third Quarter 2026 and Nine Months 2026 compared to the same prior-year periods reflect reduced new business in a competitive environment and our granular pricing actions to drive lower retention on underperforming business. Retention in our Standard Commercial Lines segment reflects these actions at 82% in Third Quarter 2026 and 81% in Nine Months 2026. While enhancing underwriting profitability is a primary focus, we are also executing on strategies to support future growth opportunities, including expanding our geographic footprint and broadening our E&S distribution capabilities with retail access.

NPE decreased 2% in Third Quarter 2026 and increased 2% in Nine Months 2026 compared to the same prior-year periods. The Third Quarter 2026 decline reflected the earned impact of lower NPW this year, while the Nine Months 2026 increase reflected growth in 2025.

The loss and loss expense ratio improved in both Third Quarter 2026 and Nine Months 2026 compared to the prior-year periods. There was no prior year casualty reserve development recorded this year, compared to unfavorable development in both the quarter and year-to-date periods last year. Current year casualty loss costs were lower in Third Quarter 2026 compared to Third Quarter 2025 reflecting the earned impact of the rate and underwriting actions during the quarter, while in Nine Months 2026, this improvement was offset by the increased loss trend assumptions that we recognized over the course of 2025 that are included in our expectations for 2026. In both Third Quarter 2026 and Nine Months 2026, property losses were higher compared to the prior-year periods due to normal variability in these losses.

As the table illustrates above, there was no prior year casualty reserve development in any segment or line of business in Third Quarter 2026 or Nine Months 2026. The unfavorable prior year casualty reserve development in Third Quarter 2025 and Nine Months 2025 was primarily driven by (i) our commercial automobile line of business that experienced increased severities in accident years 2022 through 2024 and (ii) umbrella claims within our general liability line of business driven by commercial automobile losses in accident years 2022 and 2023.

Our underwriting expense ratio increased 1.5 points and 0.4 points in Third Quarter 2026 and Nine Months 2026, respectively, compared to the prior-year periods, as lower NPE has put pressure on our underwriting expense ratio.

Standard Commercial Lines Segment

Lower NPWin Third Quarter 2026 and Nine Months 2026 compared to Third Quarter 2025 and Nine Months 2025 reflected reduced new business and targeted actions on our renewal portfolio. Stronger new business pricing, informed by our view of expected loss trends, combined with a competitive environment, drove lower acquisition rates on new business. We are leveraging our granular insights and differentiated operating model to drive higher renewal retention on our best-performing business and meaningfully lower retention on our underperforming business through appropriate rating and underwriting actions. While overall rate increases have moderated and retention has been impacted, we expect these mix improvement actions to contribute to improved profitability.

NPE decreased 2% in Third Quarter 2026 and increased 2% in Nine Months 2026 compared to the same prior-year periods. The Third Quarter 2026 decline reflected the earned impact of lower NPW this year, while the Nine Months 2026 increase reflected NPW growth last year.

The loss and loss expense ratio decreased 4.8 points in Third Quarter 2026 compared to Third Quarter 2025, primarily due to (i)nonet prior year casualty reserve development in the current year quarter compared to 3.7 points of unfavorable prior year casualty reserve development in the year-ago quarter and (ii) lower current year casualty loss costs. These items were partially offset by period-to-period variability in property losses.

In Nine Months 2026, the loss and loss expense ratio decreased 1.3 points compared to Nine Months 2025, with higher current year loss costs and catastrophe losses more than offset by improvements in prior year casualty reserve development and non-catastrophe losses. The increase in catastrophe losses wasdriven by higher frequency and severity of winter storms and thunderstorm events that impacted our footprint this year compared to last.

The details of the prior year casualty reserve development by line of business were as follows:

Prior year casualty reserve development in Third Quarter 2025 and Nine Months 2025 reflected (i) increased severities in accident years 2022 through 2024 in our commercial automobile line of business and (ii) increased severities in accident years 2022 and 2023 within our umbrella coverages in our general liability line of business related to commercial automobile claims.

Current year casualty loss costs were lower in Third Quarter 2026 compared to the prior-year quarter, primarily reflecting the earned impact of pricing and underwriting actions taken to improve rate adequacy. Higher current year casualty loss costs in Nine Months 2026 reflected the increased loss trend assumptions we recognized throughout 2025 and included in our expectations for 2026. Elevated severity trend assumptions attributable to social inflation on our general liability and commercial automobile liability lines of business, as well as elevated commercial automobile claim frequencies relative to expectations, drove the increase in current year casualty loss costs in Nine Months 2026. These increases were partially offset by lower workers compensation loss trends from decreasing claim frequencies in our 2026 expectations.

Our underwriting expense ratio increased 1.6 points in Third Quarter 2026 compared to Third Quarter 2025, as lower NPE has put pressure on our underwriting expense ratio.

Information about our most significant Standard Commercial Lines of business follows:

NPW was down in Third Quarter 2026 and Nine Months 2026 compared to the same prior-year periods, reflecting deliberate actions to enhance underwriting profitability. In sectors and markets where pricing does not align with our view of rate need, we are taking targeted underwriting actions, including (i) revising underwriting guidelines, (ii) tightening coverage offerings, and (iii) reducing writings.

NPE decreased 3% in Third Quarter 2026 and increased 3% in Nine Months 2026 compared to the same prior-year periods. The Third Quarter 2026 decline reflected the earned impact of lower NPW this year, while the Nine Months 2026 increase reflected NPW growth last year.

The combined ratio was flat in Third Quarter 2026 and decreased 0.6 points in Nine Months 2026 compared to the same prior-year periods, driven by a lower loss and loss expense ratio partially offset by higher underwriting expenses. The components of the loss and loss expense ratio follow:

The general liability line of business has experienced a long-term historical trend of meaningful severity increases, partially offset by claim frequency decreases. We attribute the increased severities to elevated social inflation, which we view as an industry dynamic characterized by higher claimant propensity for attorney representation and litigation, longer settlement times, and higher settlement values. Certain jurisdictions with expanded liability theories and higher damage awards pose increased challenges. We are closely monitoring these jurisdictions and the broader trends across our business.

These dynamics have impacted our view of current year loss costs. The increased loss trend assumptions that we recognized over the course of 2025 that are included in our expectations for 2026, drove a 0.7-point increase in current year loss costs in Nine Months 2026 compared to the same prior-year period. In Third Quarter 2026, however, current year casualty loss costs decreased 2.5 points compared to the year-ago quarter, reflecting the earned impact of the rate and underwriting actions.

We did not record any prior year casualty reserve development in Third Quarter 2026 and Nine Months 2026. We recorded $20 million of unfavorable prior year casualty reserve development in Nine Months 2025, which was driven by increased severities on umbrella coverages related to commercial automobile claims, in accident years 2022 and 2023.

The underwriting expense ratio increased 2.5 points in Third Quarter 2026 compared to Third Quarter 2025, and 0.9 points in Nine Months 2026 compared to Nine Months 2025, as lower NPE has put pressure on our underwriting expense ratio.

NPW decreased 11% in Third Quarter 2026 and 7% in Nine Months 2026 compared to the same prior-year periods, driven by underwriting actions to improve profitability, such as achieving renewal pure price increases and tightening underwriting guidelines for fleet exposures. Lower renewal pure price increases this year compared to last were driven by a reduction in rates for physical damage that were partially offset by higher commercial automobile liability rates.

NPE decreased 4% in Third Quarter 2026 and slightly increased in Nine Months 2026 compared to the same prior-year periods. The Third Quarter 2026 decline reflected the earned impact of lower NPW this year, while the Nine Months 2026 increase reflected NPW growth last year.

The combined ratio improved 15.6 points in Third Quarter 2026 and 5.5 points in Nine Months 2026 compared to the same prior-year periods, and included the following:

We did not record any prior year casualty reserve development in Third Quarter 2026 and Nine Months 2026, compared to unfavorable prior year casualty reserve development of $35.0 million in Third Quarter 2025 and $60.0 million in Nine Months 2025, driven by increased severities in the state of New Jersey for accident years 2022 through 2024. Current year casualty loss costs were lower in Third Quarter 2026 compared to the same prior-year period, primarily reflecting the earned impact of pricing and underwriting actions taken to improve rate adequacy and profitability, while in Nine Months 2026 compared to Nine Months 2025, this improvement was offset bythe increased loss trend assumptions we recognized throughout 2025 that are included in our expectations for 2026.

In the aggregate, net catastrophe and non-catastrophe property losses were 1.4 points lower in Third Quarter 2026 and 1.8 points lower in Nine Months 2026 compared to the same prior-year periods. This reduction was driven by (i) the earned impact of renewal pure price increases and (ii) period-to-period variability of catastrophe and non-catastrophe property losses.

1 Includes Inland Marine.

NPW decreased 4% in Third Quarter 2026 and 2% in Nine Months 2026 compared to the same prior-year periods, reflecting lower new business and deliberate actions to strengthen underwriting profitability.

Growth in NPE of 2% in Third Quarter 2026 and 4% in Nine Months 2026 reflected the impact of NPW growth through the first quarter of 2026, but was pressured by the impact of lower NPW for the last two quarters.

The combined ratio increased 12.2 points in Third Quarter 2026 compared to Third Quarter 2025, and 6.3 points in Nine Months 2026 compared to Nine Months 2025, and included the following:

In the aggregate, net catastrophe and non-catastrophe property losses were higher in both Third Quarter 2026 and Nine Months 2026 compared to the same prior-year periods. The increase in net catastrophe losses was driven byhigher frequency and severity of winter storms and thunderstorm events that impacted our footprint this year compared to last. This was partially offset by lower non-catastrophe property losses due to normal period-to-period variability in property losses.

NPW decreased 6% in Third Quarter 2026 and 6% in Nine Months 2026 compared to the same prior-year periods, primarily due to negative rate changes and lower new business. The rate level reductions were driven by continued decreases in workers compensation rating bureau loss costs, which form the basis for our filed rating plans, and heavily influence marketplace pricing for this line of business. Additionally, retention was lower compared to the same prior-year periods, resulting from underwriting actions taken to improve profitability.

The combined ratio decreased 5.0 points in Third Quarter 2026 and 5.6 points in Nine Months 2026 compared to the same prior-year periods and included the following:

Lower current year casualty loss costs in Third Quarter 2026 and Nine Months 2026 compared to the same prior-year periods were primarily driven by decreased claim frequencies leading to improved loss trends. In addition, the combined ratio benefited from a 1.3-point reduction in the underwriting expense ratio in Nine Months 2026 compared to the same prior-year period, primarily driven by lower commissions on this line of business.

Standard Personal Lines Segment

Lower NPW and NPE in Third Quarter 2026 and Nine Months 2026 compared to the same prior-year periods were driven by reductions in direct new business and lower renewal pure price increases. New business decreased 36% in Third Quarter 2026 and 29% in Nine Months 2026 compared to the same prior-year periods, driven by (i) market conditions, including an increasingly competitive market for auto insurance and (ii) restrictions we have in place to manage overall growth in the State of New Jersey. We have received regulatory approvals for increased rate levels in most of our footprint states and are focused on growth in our target market segment where we believe our rates are adequate. In Third Quarter 2026 and Nine Months 2026 we achieved renewal pure price increases of 8.1% and 9.3%, respectively.

The following table depicts direct new business, retention, and renewal pure price increases for the Third Quarter 2026 and Nine Months 2026:

1 Excludes our Flood direct premiums written, which are 100% ceded to the NFIP and do not impact NPW.

The loss and loss expense ratio decreased 10.8 points in Third Quarter 2026 and 4.4 points in Nine Months 2026 compared to the same prior-year periods. The absence of unfavorable prior year casualty reserve development in the 2026 periods contributed 4.9 points to this variance for the quarter and 3.3 points for the year-to-date period. Prior year casualty reserve development was as follows:

The unfavorable prior year casualty reserve development of $5.0 million in Third Quarter 2025 and $10.0 million in Nine Months 2025 was primarily driven by increased severities in accident year 2024 related to the New Jersey portfolio.

Lower non-catastrophe property losses and current year casualty loss costs reduced the loss and loss expense ratio in Third Quarter 2026 and Nine Months 2026 compared to the same prior-year periods. The decrease in non-catastrophe property losses was primarily due to normal period-to-period variability associated with such losses. These amounts were partially offset by higher net catastrophe losses compared to the same prior-year periods due to higher frequency and severity of weather-related catastrophe events impacting our footprint.

Our underwriting expense ratio increased 4.0 points and 1.6 points in Third Quarter 2026 and Nine Months 2026, respectively, compared to the prior-year periods, as lower NPE has put pressure on our underwriting expense ratio.

E&S Lines Segment

Increased competition in the marketplace and our continued underwriting discipline contributed to a decline in NPW of 2% in Third Quarter 2026 and 1% in Nine Months 2026 compared to the same prior-year periods. This NPW decline was primarily due to more capacity entering the excess and surplus lines marketplace and the admitted markets' expansion in appetite for business previously written by excess and surplus lines companies. NPW included the impact of the following:

Despite the decline in NPW during 2026, NPE grew 1% in Third Quarter 2026 and 4% in Nine Months 2026 compared to the same prior-year periods, driven by growth in NPW in 2025 and the corresponding earnings of those premiums written.

The loss and loss expense ratio increased 10.3 points in Third Quarter 2026 compared to Third Quarter 2025, impacted by (i) higher current year casualty loss costs, primarily driven by higher embedded severity assumptions due to social inflation, (ii) higher non-catastrophe property loss and loss expenses, reflecting normal period-to-period variability associated with property losses, and (iii) higher net catastrophe losses due to higher frequency and severity of weather-related events that impacted our footprint.

The loss and loss expense ratio increased 3.5 points in Nine Months 2026 compared to Nine Months 2025. In Nine Months 2026, higher current year casualty loss costs and non-catastrophe property losses were partially offset by lower net catastrophe losses compared to Nine Months 2025, which included losses from the California Palisades Fire that impacted the first quarter of 2025.

Reinsurance

We successfully completed negotiations of our July 1, 2026 excess of loss treaties that cover Standard Commercial Lines, Standard Personal Lines, and E&S Lines.

We renewed the Casualty Excess of Loss Treaty (“Casualty Treaty”) with coverage for $87 million in excess of a $3 million retention per loss occurrence, which is the same as the expiring treaty. We continue to retain a portion of the first layer through an 8% co-participation, compared to a 20% co-participation in the expiring treaty. The 2026 treaty year deposit premium increased primarily due to increased premium rates and lower co-participation in the first layer.

We also renewed the Property Excess of Loss Treaty (“Property Treaty”) with the same retention as the expiring treaty, but with a $20 million increase in limit. The treaty now provides coverage for $115 million in excess of a $5 million retention for losses on a per-risk basis. The treaty year deposit premium decreased modestly, primarily driven by a reduction in rates.

The following table summarizes the Casualty Treaty and Property Treaty arrangements covering our Insurance Subsidiaries:

Investments

Our Investments segment's objectives are to maximize the economic value of our investment portfolio by achieving stable, risk-adjusted after-tax net investment income and generating long-term growth in book value per share. Our strategies consider prevailing market conditions, our enterprise risk tolerances, and other risk implications by:

•Maximizing the portfolio's overall total return by investing (i) the premiums from our insurance operations, (ii) amounts generated through our capital management strategies, including debt and equity security issuances, and (iii) profits of our business; and

•Maintaining (i) a well-diversified portfolio across issuers, sectors, and asset classes and (ii) a fixed income securities portfolio with high credit quality and acceptable duration and maturity profiles to provide ample liquidity.

The effective duration of our fixed income and short-term investments was 4.5 years as of September 30, 2026. We monitor and manage the effective duration to maximize yield while managing interest rate risk at an acceptable level. We buy and sell investments with the intent of maximizing investment returns in the current market environment, while balancing capital preservation and ensuring adequate liquidity to support our insurance business.

Our fixed income and short-term investments represented 91% of invested assets at September 30, 2026, and 92% at December 31, 2025, and had a weighted average credit rating of “A+” as of both dates. Investment grade holdings represented 96% of the total fixed income and short-term investment portfolio as of September 30, 2026, and 97% as of December 31, 2025.

For further details on the composition, credit quality, and various risks to which our portfolio is subject, see Item 7A. “Quantitative and Qualitative Disclosures About Market Risk.” of our 2025 Annual Report.

Invested assets increased $184.3 million as of September 30, 2026, compared to December 31, 2025, primarily reflecting our active investment of operating cash flows, which were 23% of NPW in Nine Months 2026. Invested assets included a $433.0 million increase inpre-tax net unrealized losses in our fixed income portfolio primarily due to higher interest rates as of September 30, 2026, compared to December 31, 2025.

Net Investment Income

Net investment income earned components were as follows:

The increase in after-tax net investment income earned in both Third Quarter 2026 and Nine Months 2026 compared to the same prior-year periods, was primarily driven by (i) active portfolio management resulting in higher after-tax portfolio yield and (ii) operating cash flow deployment.

Realized and Unrealized Gains and Losses

When evaluating securities for sale, our general philosophy is to reduce our exposure to securities and sectors based on economic evaluations of whether (i) the fundamentals for that security or sector have deteriorated or (ii) the timing is appropriate to trade opportunistically for other securities with better economic-return characteristics. Net realized and unrealized gains and losses for the indicated periods were as follows:

The change in net realized and unrealized investment losses in Third Quarter 2026 and Nine Months 2026 compared to net realized and unrealized investment gains in the same prior-year periods, was primarily driven by (i) a decrease in valuations reflecting the current public equities market and (ii) an increase in net credit loss expense on fixed income investments, primarily due to higher interest rates in Third Quarter 2026 and Nine Months 2026 compared to the same prior-year periods. The higher interest rates increased unrealized losses on our fixed income investments, thereby increasing the amount of recognized credit losses.