California’s Workers’ Compensation Insurance Rating Bureau (WCIRB) released its most recent Quarterly Experience Report on workers’ comp cost trends.

Predictably, the report leans into the narrative, popular among insurer advocates, that Cumulative Trauma (CT) claims are a primary driver of California’s excessive comp expenses. The WCIRB fails to substantiate its conclusions, relying, as it usually does, on its black box of insurer-supplied, unverifiable data.

In chart after chart, the WCIRB either reports a troubling trend for which it blames CT claims, or reports a benign trend that it predicts will turn ugly once CT claims mature.

The WCIRB projects a dismal workers’ comp combined ratio of 127% for 2025 (the combined ratio is the key metric by which insurer profitability is measured; anything under 100% indicates profitability). Yet multiple indicators undercut this projection, including data from the National Association of Insurance Commissioners (NAIC) suggesting profitability for California insurers and the California State Compensation Insurance Fund (CA State Fund)’s reported 2025 combined ratio of 87.4%.

The WCIRB invokes CT claims to explain (or explain away) the “data” reported in eight out of its 14 charts, repeatedly (and only) self-referring to its own separate report on CT claims, for which the underlying data are also unavailable.

The WCIRB informs state government decisions, shapes media narratives, and directly influences the rising premium rates California employers pay for workers’ comp coverage. Yet, legislators, regulators, and industry voices accept the WCIRB’s conclusions with barely a question.

Employers are paying for this lack of scrutiny.

WCIRB: CT Makes Comp Costs Go Up, Down, and Sideways

According to the WCIRB, CT claims usually explain rising costs, while flat or falling costs are temporary reprieves until CT claims’ delayed effects hit. The table below lists each instance in which the Quarterly Experience Report applies this all-purpose CT excuse.

Eight charts use CT claims to explain trends (or predict reversals in trends), yet not one actually quantifies how. To back the report’s claims, the endnotes cite the WCIRB’s CT study, whose underlying data is also unavailable. The WCIRB’s evidence for its black box is another black box.

Even when the trends are good news for insurers, the Quarterly Experience Report repeatedly warns of impending doom once the effects of CT claims materialize, as they take longer to develop and often involve no medical costs in the first year or two of the claim.

The Dastardly Los Angeles Attorney Theory

The report’s Chart 10 (below) tracks Allocated Loss Adjustment Expenses (ALAE), which include the cost of insurers’ defense attorneys. According to the WCIRB, ALAE growth is “associated in part with” a higher frequency of CT claims, which are more likely to involve attorneys.

The WCIRB then goes on to stoke an increasingly popular theory among payer advocates:

“...more injured workers outside Los Angeles being represented by Los Angeles-based law firms.”

The implication is inescapable, even if the evidence is nonexistent: dastardly LA lawyers are spreading a plague of CT claims beyond their usual territory.

This mirrors a recent CWCI report, which carefully noted that no evidence established a causal link between the expansion of LA-based law firms and the rise in CT claims. Like the CWCI, the WCIRB also offers no hard evidence to support its assertions about LA lawyers.

Attorney involvement in claims involves a multitude of factors. As daisyNews recently explored, a study of 400,000 claims found that poor communication with injured workers and treatment delays drastically increased the odds that an injured worker would engage an attorney (which, in turn, requires the insurer to engage attorneys). Attorney involvement rates in California were double the average of all states studied.

Moreover, our Utilization Review (UR) data indicate that payers collectively approve only about 70% of providers’ treatment requests, with approval rates varying widely across payers. Add the abysmally low rate (about 10%) at which Independent Medical Review overturns treatment denials, and it’s easy to see what might really be driving up attorney involvement and overall ALAE.

The Mirage of an Insurer Crisis

Perhaps the most significant projection the WCIRB makes is that the combined ratio for 2025 will be 127%, the “highest in over 20 years,” according to the WCIRB.

Again, the WCIRB’s data is entirely self-reported by its insurer members and unavailable to the general public. Meanwhile, multiple facts and data sources, including some of the Quarterly Experience Report’s own contentions, counter the idea that CA insurers are struggling to make ends meet:

• The workers’ comp line of insurance is decidedly profitable nationally.
• The WCIRB report notes in Chart 1 that “Written premium in the first six months of 2026 is 5% higher than during the same period in 2025, suggesting growth for the year.”
• NAIC data show healthy loss ratios for California insurers.
• CA State Fund, the state’s non-profit insurer of last resort, is doing fantastic, charting a healthy combined ratio and issuing hundreds of millions in dividends.

As daisyNews continues to remind readers, the WCIRB has been credibly accused of “skewing” its data to make insurers appear less profitable.

Painting this sad picture is in WCIRB members’ interests. The WCIRB has consistently advocated for raising California employers’ comp premium rates, and must justify those recommendations with…something, even if that “something” is reports that don’t withstand real scrutiny.

Show the Data or Drop the Narrative

In CT claims, as well as billing codes for “unlisted” medical services, payer advocates like the WCIRB have a convenient culprit for the ills of California’s comp system.

While it may be the case that CT claims deserve real analysis, reports like this one don’t provide any substantive insight.

Instead, they keep the focus on the actions of injured workers, the providers who treat them, and the attorneys who represent them. Meanwhile, the cost-driving choices made by insurers, their vendors, and the private equity interests that benefit from excessive administrative and legal friction remain in the background of the conversation.

California needs a thorough accounting of the real mechanisms behind high comp costs, not insurance-industry press releases.

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