Surplus Lines Premiums Surge to $46.2 Billion in First Half of 2025

The U.S. surplus lines market generated $46.2 billion in premium across 15 stamping office states during the first half of 2025, marking a 13.2% increase over the same period last year and demonstrating continued momentum in the sector, according to the 2025 midyear report from the Wholesale & Specialty Insurance Association (WSIA).
Stamping offices are non-governmental organizations that operate in 15 states to oversee the unique requirements of surplus lines transactions. Stamping office states accounted for 63% of all U.S. surplus lines premium volume in 2024.
Market Growth Spans Multiple Lines of Business
The midyear performance builds on 2024’s robust annual results of $81.6 billion in premium in the stamping office states, which represented 12.1% growth year-over-year, the WSIA noted. Transaction volume also increased substantially, with 3.7 million premium-bearing items filed with stamping offices through mid-2025, reflecting a 12.4% rise compared to the previous year.
Commercial liability and commercial property coverage maintain their dominance within the surplus lines segment, accounting for 36.6% and 34.0% of premiums at midyear, respectively. Commercial liability premiums were 19.8% higher at midyear, compared to a year earlier, while property premiums were up only 5.7%.
Auto liability and residential property lines are experiencing faster growth rates of 29.1% and 24.8%, respectively, though they still represent relatively small portions of the overall market at 3.6% and 5.3% respectively, among the stamping office states.
Increasing premiums across nine key business lines—including auto liability, auto physical damage, disability/A&H, inland marine, liability, multi-peril, professional liability, property, and residential coverage—indicate the market’s diversification as it responds to evolving coverage needs, according to the WSIA.
State Performance Reveals Regional Market Dynamics
Arizona emerged as a standout performer with an 18.6% increase in surplus lines premiums over mid-year 2024, the report noted.
“Disability/A&H, up 68.7%, and auto physical damage, up 57.0%, grew substantially but still constitute relatively small pieces of the Arizona surplus lines market,” said Edward Dresselhuys, executive director of the Surplus Line Association of Arizona. “Our largest lines, general liability and property, grew modestly but professional liability was up 36.6% which significantly drove growth.”
Idaho presented a contrasting scenario as the only state experiencing a decrease in surplus lines premiums, falling 16% through mid-year 2025 due to declines in liability and commercial property lines.
However, Carrie Negrette, executive director of the Surplus Line Association of Idaho, noted that despite the recent decline, “Idaho premium volume is still up 82% since mid-year 2022.”
New York’s performance — with an 18.6% increase in premiums and 20.9% increase in transactions during the first half — highlighted regional market resilience, with the state’s surplus lines leadership emphasizing the sector’s adaptability to changing risk landscapes.
“The resilience demonstrated by New York’s E&S market underscores their critical role in addressing complex and emerging coverage needs across the state,” said Janet Pane, CEO & executive director of the Excess Line Association of New York. “This performance reflects the sector’s ability to adapt to evolving risk landscapes while maintaining underwriting discipline and address the coverage gap for consumers in times of strong market demand.”
View the midyear report here. &