California is experiencing a significant uptick in cumulative trauma claims, which are now driving up both medical-legal costs and litigation within the workers' compensation system. These claims, which attribute injuries to prolonged workplace activities rather than single incidents, are more prevalent than ever, impacting insurer profitability and raising questions about claim-handling practices.
Financial Impact on Insurers
The latest findings from the Workers Compensation Insurance Rating Bureau of California (WCIRB) reveal a troubling trend: The projected combined loss and expense ratio is expected to rise to 127% in 2025, up from 124% in 2024. This marks the second consecutive year where the ratio exceeds 120%, reflecting the financial strain placed on insurers. While written premiums have held steady at approximately $15.6 billion, the average charged rate has fallen to $1.56 per $100 of payroll—the lowest level recorded in over half a century, according to Tony Milano, WCIRB's executive vice president and chief actuary.
Rate Increases Amid Persistent Claims
Compounding the issue, the California Department of Insurance recently approved a 6.6% average advisory pure premium rate increase effective September 1, 2026, following an 8.7% rise the prior year. Despite these hikes, the current advisory rates remain a staggering 46% lower than the peak observed during 2014-2015.
Contentious Denial Practices
During discussions at the WCIRB's annual conference, concerns regarding the rapid denial of cumulative trauma claims were raised. Adam Dombchik, managing partner at Gordon, Edelstein, Krepack, Grant, Felton and Goldstein, pointed out that many claims are often denied within 14 to 21 days without adequate investigation. He advocated for a more receptive approach from employers, particularly in cases involving long-term employees showing clear signs of physical wear.
Conversely, Scotty Benton, vice president at Sedgwick, emphasized that denials are not automatically issued; each claim undergoes careful evaluation based on documented reasons linked to an active investigation. The underlying issue may lie in the medical-legal system, which often delays crucial evaluations that impede timely decisions, frequently placing claims in a state of "conditional denial." Notably, over 80% of cumulative trauma claims reportedly involve attorney representation, leading to prolongations of unresolved claims.
Defining Features of Cumulative Trauma Claims
According to Jeff Adelson, a partner at Bober, Peterson & Koby, the initial awareness of cumulative trauma claims can be murky, often surfacing only when an adjudication request is filed. At that point, employers may lack critical information regarding the employee's prior reports of pain or time off work. Adelson underscored that an initial denial doesn't seal the fate of a claim; rather, ongoing discussions and document retrieval can eventually sway insurance companies to change their stance based on strengthened evidence.
Systemic Challenges and Long-Term Outlook
Sure Log, of counsel at Michael Sullivan & Associates, articulated that California’s regulatory environment, which allows only a “contributing cause” for compensability, predisposes cumulative trauma claims to easier acceptance. The 90-day window for accepting or denying claims adds to the likelihood of outright denials; if insurers fail to act within this timeframe, claims automatically become presumed compensable. Additionally, the complexities surrounding claims filed post-termination only add further scrutiny to the claim process.
The financial stakes behind these claims and their subsequent denials are underscored by the rising utilization of medical-legal services associated with cumulative trauma claims, which surged by 38% from 2020 to 2024, as compared to just 2% for other claim categories. Allocated loss adjustment expenses per indemnity claim reached $13,860 in 2025, reflecting a roughly 9% annual growth rate since 2021. Compounding this, many cumulative trauma claims see no medical payments during their first 18 months, and 22% of these claims remain unresolved after five years.
Shifting Claim Patterns Across California
Recent analysis reveals that the surge in cumulative trauma claims cannot be solely attributed to labor market dynamics, including population shifts or changes in worker tenure, according to a report by the California Workers' Compensation Institute. Cumulative trauma claims accounted for 16.5% of all California workers' compensation claims in 2025, up from 9.1% in 2018, particularly noticeable after 2021. This increase is driven more by a higher number of individual workers filing claims rather than a spike in claims per individual.
Moreover, the report highlights a notable change in applicant attorney involvement, with Southern California law firms now representing 79% of cumulative trauma cases involving Northern California employers—a substantial increase from 23% in 2019. The expansion of remote hearings during the pandemic seems to have played a role in this shift, although the report did not explicitly link this trend to the overall increase in claims.
Geographically, Los Angeles tops the state in cumulative trauma claim rates, reaching 22.9% in 2025, while the Inland Empire/Orange County region saw a 10-point increase to 19.8%. Additionally, the Valleys region reported a staggering 136% rise in claim volume since 2018, suggesting that the growth isn’t confined to historically high-claim areas.
With claims on the rise and the system under pressure, Benton argues that resolving these challenges will require more than case-by-case adjustments. Employers should prepare for cumulative trauma claims to continue exerting upward pressure on costs for the next three to five years as the debate around claim denials and their financial implications intensifies.