California workers’ compensation premium growth leveled off as rates stabilize, but rising cumulative trauma claims continue to drive claim frequency higher, a new report shows.

The Workers’ Compensation Insurance Rating Bureau of California released its 2026 State of the System report, examining premium levels, claim activity, system costs and market conditions.

Related: WCIRB: 2025 California Workers’ Losses and Expenses 102% of Earned Premium

Average charged rates reached the lowest level in more than 50 years in 2025 but are plateauing. In 2025, advisory pure premium rates increased for the first time in a decade, with a further 6.6% increase approved effective September 1, 2026, the WCIRB report shows.

However, claim frequency rose in California in the last few years.

“The share of indemnity claims involving CT injury increased significantly over the past four years and is the primary driver of frequency increases in California,” the report states. “WCIRB research shows that recent CT claims have several unique characteristics compared to other types of claims, including a high share of claims filed post-termination, high rates of representation and different medical cost patterns. CT claims are also often reported later and stay open longer.”

Related: WCIRB: California Comp Written Premiums ‘Relatively Stable’ Compared to Pandemic

The report also shows that the combined ratio remains “near historically high levels.”

The WCIRB projects the accident year combined ratio for 2025 is 127%, the highest in more than 20 years and the second consecutive year of a combined ratio over 120%. Combined ratios in California continue to be above those for the rest of the country, the report shows.

Written premiums from 2022 through 2025 remained relatively stable compared to the large swings during the pandemic. Written premium for the first quarter of this year is roughly 3% higher than the first quarter of 2025, suggesting modest premium growth in 2026, according to the WCIRB.

Topics California Claims Connecticut