The surplus lines market closed 2025 at a record $143.3 billion in direct premium written, up 10.4% from $129.8 billion the year before, according to AM Best's annual US Surplus Lines Market Segment Report. The report recorded an eighth consecutive year of double-digit growth for the sector but the more telling detail is what's changing underneath the numbers.
After years of hard market conditions funneling commercial risks into the excess and surplus (E&S) lines channel, the cycle is shifting. Admitted carriers are returning to lines they had pulled back from. Capacity is abundant across much of the market, and premium growth is moderating even as it remains in double-digit territory.
AM Best notes that the trend of moderation, particularly for domestic surplus lines companies, "was further evident in 2025." That shift is already reshaping how brokers approach placement decisions.
How deeply embedded surplus lines has become in commercial placement is visible in the line-level data. Surplus lines carriers wrote more than $51 billion in general liability direct premium in 2025. That was 39 percent of the entire P&C industry's general liability volume.
The market share story spans a longer arc. Surplus lines now represent 12.9 percent of total P&C direct premiums written, up from 3.6 percent in 2000. Their share of commercial lines premium has grown from 7.1 percent to 27.5 percent over the same period.
The central placement question now is which risks stay in the surplus lines channel as the admitted market grows more competitive. AM Best's position is that complex, hard-to-model exposures won't be going anywhere soon.
Commercial property in catastrophe-exposed geographies, large construction projects including data centers, environmental liability, and professional lines with rising claim severity all fall into that category. General liability and commercial auto also look set to remain in E&S because social inflation and third-party litigation funding continue to drive claim costs up. AM Best expects underwriters on those lines will hold pricing firm even as other segments soften.
The cyber market is splitting along similar lines. AM Best identifies two distinct cyber markets forming. Surplus lines carriers are writing the majority of primary and excess cyber-specific policies, while the admitted market handles basic endorsements to broader commercial policies. That division is likely to hold as long as claim severity and evolving exposure definitions make standardized admitted-market forms difficult to sustain.
Two forces are compressing broker placement options in the near term. Abundant capacity and the re-entry of admitted carriers into some lines are pulling rates down on commercial property and softening parts of the casualty market.
The risks that drove a decade of E&S growth still carry placement complexity the admitted market hasn't resolved. Cyber, AI-related liability, and catastrophe-prone property all fall into that group. The line between the two markets keeps shifting as admitted carriers reassess their appetite.
Where AM Best's data offers direct relevance to placement conversations is on carrier financial strength. Through mid-2026, 100 percent of AM Best's 105 domestic professional surplus lines rating units fell in the top four issuer credit rating categories.
The figure for the total P&C industry was 97.2 percent. Ninety-seven percent of surplus lines carrier ratings fall in the Exceptional, Superior, or Excellent categories, compared with 86 percent for the admitted market. There were no surplus lines impairments in 2025 or through the first half of 2026, against five admitted P&C company impairments in 2025. Since 2003, AM Best has recorded just one surplus lines company impairment, against 311 in the admitted market over the same stretch.
Those numbers reflect a discipline of underwriting and risk selection that, in an increasingly competitive and softening market, will face real pressure in the years ahead.
The distribution picture adds context for brokers who rely on wholesale partners. Wholesale brokers without binding authority remain the primary surplus lines channel at 45 percent of premium in 2025. MGAs and program managers generated nearly 25 percent, up from 23.7 percent the prior year, on a trend that has run steadily since 2018.
The share of business routed through wholesale brokers and MGAs in the surplus lines market has shifted materially in recent years, and AM Best's analysis draws on direct surveys with surplus lines carriers and their distributors. It makes the case that MGAs and wholesalers with genuine class-specific expertise are separating from the rest of the market. Deep, specialized knowledge of specific risk classes is harder to replicate and increasingly what insurers are looking for in wholesale partners.
The report is also direct about agentic AI. AM Best found that distributors using AI across submission intake, pre-underwriting evaluation, and quote-to-bind produced better results than those treating it as a single-task fix. The early movers built that platform approach across the distribution lifecycle. Those that started first are compounding the advantage. AM Best's conclusion is that agentic AI is in production, and the gap between early adopters and the rest of the market is widening.
The underwriting discipline behind those financial strength figures will face its first real test in a softening market. Through a decade of hard conditions, surplus lines carriers had the advantage of pricing power and a constrained admitted market. AM Best's 2026 report suggests that advantage is fading on some lines. What replaces it, whether that is specialization, AI adoption, or underwriting rigor, will determine which carriers and distributors hold their ground.
