AM Best: Surplus lines stamping office DPW grows 12% to $81.6 billion in 2024

By Chris Munro

April 22 - (The Insurer) - The 15 surplus lines state service and stamping offices collectively booked premium volume growth of 12.1% to $81.6 billion in 2024 as continued challenges in certain standard market segments continued to push business into the channel, a new report from AM Best has highlighted.

California, Florida, Texas, New York, Illinois, Pennsylvania, Washington, North Carolina, Arizona, Minnesota, Oregon, Nevada, Mississippi, Utah and Idaho are the 15 states that have surplus lines service and stamping offices.

In 2024, those states generated $81.6 billion of direct premiums written (DPW), up from $72.8 billion in 2023, figures from AM Best show.

The 12.1% surplus lines premium volume growth that group generated in 2024 is a continuation of the significant expansion of the sector.

Across the last full three years from 2022 to 2024, premiums produced by the 15 service and stamping offices increased by 28.8%, according to AM Best.

That growth is yet further evidence of the broader expansion within the surplus lines market in recent years.

As AM Best noted in its Challenging Market Conditions Yield Opportunities for Surplus Lines’ Insurers study, the US surplus lines market booked double-digit year-on-year premium growth from 2018 to 2023 as wholesale brokers tapped the market with greater frequency to explore coverage solutions for businesses amid expanding risks.

Growth of the surplus lines market’s premium underscores the sector’s ability to adapt to shifting demands, AM Best said, with carriers able to utilise the market’s freedom of rate and form to provide coverage for troubled risk classes and business lines when admitted market carriers are reticent to do the same.

The states of California, Florida, Texas and New York consistently account for the largest share of US surplus lines DPW annually.

Based on services and stamping office data, California, Florida, Texas and New York accounted for more than 75% of total US surplus lines DPW in 2024.

The ratings agency said several segments have been key in contributing to the growth in premiums seen by the surplus lines offices in the 2022 to 2024 stretch.

Those segments include business lines that directly experienced turbulence following the Covid-19 pandemic from macroeconomic pressures.

“Although personal lines coverage, specifically homeowners insurance, remains a relatively small part of the overall surplus lines market, increased writings in that segment has contributed to the consistent premium growth for surplus lines or non-admitted insurers,” said AM Best.

“Many states, in addition to multiple lines of business, have been key contributors to the momentum buoying the surplus lines market,” the rating agency noted.

California’s homeowners market was already challenged prior to the recent record-breaking wildfire losses that struck in early 2025.

AM Best said extreme weather, including heavy rains that subsequently caused mudslides, left writers of homeowners and commercial property coverage in California with unfavorable results.

At the same time, some admitted insurers reassessed their appetite for property business, and that pushed more risks into the surplus lines market.

“The California property market is likely to face more challenges in the near term, and surplus lines’ insurers could look to fill supply gaps as more admitted insurers become reluctant to provide market capacity in areas of the state,” said AM Best.

“If this occurs, it would be similar to market dynamics that occurred previously in Florida and Louisiana following the impact of elevated weather-related losses,” the rating agency suggested.

The homeowners challenges extend well beyond California though, and that has caused more business to move into the surplus lines segment.

Indeed, AM Best said surplus lines’ homeowners premium has more than doubled during the last six years, from $1.0 billion in 2018 to $2.2 billion in 2023.

Liability business has also helped to fuel the growth of the surplus lines market, AM Best noted.

“AM Best has found the coverages which fall under the general liability banner have combined to consistently represent the largest portion of the surplus lines market from a DPW perspective,” the agency said.

“The combination of general liability (36.9%) and commercial property (32.9%) coverage represented almost 70% of surplus lines market premium written through the service and stamping offices over the last three years,” it added.