AM Best's Decade-High P&C Profit Tests Reserve Durability

The U.S. property/casualty industry closed 2025 with a 92.9 combined ratio and $60.9 billion in net underwriting gains, its strongest result in a decade (AM Best, July 2026).

Favorable prior-year development contributed $18.1 billion of that, and independent tracking from Assured Research puts the gain almost entirely in personal auto liability, with the casualty book still $12.5 billion short. A decade-best headline sits on a bifurcated reserve position.

Key Takeaways

• Personal auto liability swung from a $1.9 billion redundancy to $12.0 billion in twelve months, while other liability occurrence stayed $12.5 billion deficient after two consecutive years of strengthening.
• The accident-year combined ratio is 94.9, two full points above the 92.9 calendar-year figure, which is the size of the reserve contribution inside the headline.
• $10.5 billion of the casualty deficiency sits in accident years 2021 through 2024, against a $200 million deficiency in the still-green 2025 year.
• Two credible reserve views disagree in sign. AM Best re-estimates a $9 billion industry deficiency net of statutory discount; Assured Research computes a $20.7 billion redundancy.
• AM Best already projects a 96.9 combined ratio for 2026, with commercial lines at 96.3, as premium growth slows from 6.1% to 4.0%.

What the 92.9 Is Made Of

Best's Market Segment Report puts the industry combined ratio at 92.9 for 2025, improved 3.7 points from 96.6. Net underwriting gain nearly tripled to $60.9 billion from $22.1 billion. Net premiums written rose 4.7% to $940.7 billion and premiums earned 6.1% to $923.3 billion, against $615.7 billion of losses and loss adjustment expenses and $241.2 billion of underwriting expenses (Insurance News Net, July 2026).

Catastrophe losses added 7.6 points, down from 8.8, so a milder accident year let underlying results show through the calendar-year figure. Net investment income climbed 9.1% to $91.4 billion and pretax operating income 43.2% to $153.1 billion. Net income fell 9.5% to $150.9 billion, entirely on a 71.6% decline in realized capital gains tied to a combined $60 billion drop across three Berkshire Hathaway subsidiaries (captive.com).

Personal lines carried it. Personal auto liability underwriting income more than doubled to $28.9 billion from $13.8 billion, and homeowners multiperil swung to a $16.8 billion gain from a $1.5 billion loss while absorbing the early-2025 California wildfire losses, with incurred net losses down 7.1%. Personal lines cleared more than $45 billion of underwriting profit and commercial lines added over $19 billion, reversing $51 billion of cumulative underwriting losses from 2021 through 2023.

The gap that matters is between bases. The accident-year combined ratio is 94.9, two points above the calendar-year 92.9, which is the $18.1 billion of favorable prior-year development showing up as the difference.

Two Reserve Views That Agree on the Line Level

Assured Research, run by Fellow of the Casualty Actuarial Society William Wilt, computes a $20.7 billion industry redundancy at year-end 2025, up from $2.0 billion a year earlier (Carrier Management, March 2026). AM Best's own actuaries re-estimated year-end 2024 statutory reserves net of discount and still found a $9 billion deficiency, roughly $10 billion better than originally projected.

The two are not measuring the same thing: one is a rating-agency re-estimation net of discount, the other a bottom-up reconstruction from Schedule P triangles. The sign disagreement matters less than what both show underneath.

Line of business	Year-end 2024 position	Year-end 2025 position
Private passenger auto liability	$1.9B redundancy	$12.0B redundancy
Other liability (occurrence)	$15.0B deficiency	$12.5B deficiency
Industry total (all lines)	$2.0B redundancy	$20.7B redundancy

Personal auto's release is the 2021-2023 severity shock unwinding on schedule. A carrier booking accident year 2023 assumed continued acceleration in bodily injury severity when it selected initial development factors; paid losses came in below that pick, and the margin released two to three years later. Assured Research places $5.0 billion of the $12.0 billion redundancy in accident years 2022 through 2024, including $3.0 billion in 2024 alone, with another $6.7 billion in the green 2025 year. Auto physical damage tells the frequency-side version, with a booked 55.7 loss ratio for accident year 2025.

Other liability occurrence had no such cushion. Of its $12.5 billion deficiency, $10.5 billion sits in accident years 2021 through 2024, the vintages exposed to nuclear verdicts and litigation funding, against $200 million in 2025. Long-tail claims develop years later than personal auto claims, so a clean current year says little about the older vintages.

That is what the 19 consecutive years of favorable industry development now amount to at the line level. Citing the streak as evidence that a commercial casualty book is conservatively reserved overstates what the data supports once personal auto is removed, and the same asymmetry runs through trend selection: personal auto's development says rate adequacy has been restored, while other liability's persistent 2021-2024 deficiency says the loss trends chosen in that period understated severity.

The Release Is a Depleting Asset and Casualty Is Still Adding

Commercial auto shows the pattern most sharply. Its underwriting loss narrowed to $1.9 billion from $4.9 billion, and that improvement arrived alongside $2.0 billion of new reserve deficiencies added during 2025, concentrated in the 2023 and 2024 accident years. Other liability occurrence improved to an $11 billion underwriting loss from $13.7 billion with its combined ratio falling to 114.7 from 120.3, still the worst-performing major line, on net losses incurred approaching $50 billion.

"Casualty lines, specifically commercial auto liability and other liability, remain pressured by adverse development and elevated claims severity," said AM Best senior industry analyst Christopher Graham (Claims Journal, July 2026).

Workers' compensation sits between the two and is moving the wrong way. Assured Research finds the line still materially redundant at year-end 2025 without attaching a figure, but that redundancy has been thinning for several years as severity trend and medical cost inflation erode the buffer built in the mid-2010s hard market. Personal auto's redundancy is building while workers' comp's is shrinking, so two lines that both post a favorable position are traveling in opposite directions.

The capital cushion is genuine. Policyholder surplus grew 11.4% to $1.19 trillion, a $122.9 billion gain, which gives carriers room to absorb continued casualty strengthening without solvency stress. What it does not support is extrapolating the combined ratio. AM Best's February outlook already projects 96.9 for 2026, with commercial lines at 96.3, as premium growth slows to 4.0% from 6.1% and rate fails to keep pace with loss cost inflation (Insurance Journal, February 2026). The releases funding the 92.9 come from short-tail lines that have already re-priced; the deficiencies still being added come from the longest-duration liabilities on the book.

Further Reading

• P&C Q1 2026 Combined Ratio: Reading the Reserve Quality Signal - the framework for separating catastrophe timing, current-year margin, and prior-year development in a single quarter's combined ratio.
• A Reserve Adequacy Playbook for the P&C Soft Market - how reserving actuaries should stress-test favorable development as pricing cycles turn.
• NCCI Flags Eroding Workers' Comp Reserve Redundancy as the Pricing Cycle Turns - the same short-tail-versus-long-tail reserve dynamic playing out in workers' compensation.
• Aon Reframes Social Inflation as Litigation Abuse in Its Casualty Reserve Outlook - the industry vocabulary shift behind the other-liability-occurrence deficiency this article quantifies.
• Nuclear Verdict Severity Forces a Repricing of Umbrella and Excess ILFs - the increased limits factor mechanics driving the accident years 2021-2024 deficiency in other liability occurrence.
• Machine Learning Jury Award Models Reach Commercial Auto Reserving - how carriers are trying to get ahead of the severity trend behind the commercial auto reserve deficiencies AM Best flagged for 2025.