California Court Clarifies WCAB Arbitration Date for Cumulative Injuries

A workers’ compensation case involving a former New York Yankees player has clarified when California law requires arbitration of an insurance-coverage dispute arising from a cumulative injury.

In Travelers Indemnity Co. v. Workers’ Compensation Appeals Board (Zeber) (2025) 111 Cal.App.5th 568, the Fourth District Court of Appeal held that mandatory arbitration under Labor Code section 5275 applies only when the legally defined “date of injury” is January 1, 1990, or later. For a cumulative injury, that date must be determined under Labor Code section 5412—not simply by using the final day of workplace exposure.

Read the published opinion on CourtListener.

A Claim Based on a Baseball Career Decades Earlier

George Zeber filed a workers’ compensation claim in May 2017 alleging cumulative trauma while playing professional baseball for the New York Yankees from 1968 through 1978. The workers’ compensation judge found that Zeber sustained an injury arising out of and in the course of his employment. The judge deferred permanent-disability, apportionment, and attorney-fee issues while the medical record was developed.

The claim also presented an insurance question. Travelers Indemnity Company disputed whether the Yankees had coverage administered by Travelers during the relevant period. The WCAB eventually deferred the coverage issue and directed that it be decided through mandatory arbitration.

Travelers sought appellate review, arguing that mandatory arbitration was unavailable because Zeber’s work exposures ended years before the arbitration statute became effective.

When Does Section 5275 Require Arbitration?

Labor Code section 5275 requires arbitration of specified workers’ compensation disputes, including disputes over insurance coverage. The statute was enacted as part of the Margolin-Bill Greene Workers’ Compensation Reform Act of 1989, which became effective on January 1, 1990, and applied to injuries occurring on or after that date.

The Court of Appeal therefore held that January 1, 1990, is the trigger date for mandatory arbitration under section 5275. It rejected an alternative 1994 date that had appeared in some earlier WCAB decisions.

The WCAB could not avoid that statutory limitation by relying on a regulation granting workers’ compensation judges broad authority to adjudicate issues. An administrative regulation cannot enlarge the scope of the governing statute.

Section 5412 Defines the Date of a Cumulative Injury

Identifying the statutory trigger date did not resolve Zeber’s case because cumulative injuries have a specialized date-of-injury rule.

Under Labor Code section 5412, the date of a cumulative injury is when two conditions coincide: The worker has suffered disability, and the worker knew—or reasonably should have known—that the disability was caused by present or prior employment. That date can be later than the final exposure to the activities that produced the injury.

Travelers argued that Zeber’s injury date should be the last day of his Yankees employment in 1978. The court disagreed. California’s workers’ compensation definitions expressly use section 5412 for cumulative injuries, and the Legislature used the established term “date of injury” when it enacted section 5275.

Accordingly, the relevant question was not merely when Zeber last played professional baseball. It was when his disability and the required knowledge of industrial causation first existed together.

Knowing About a Claim Is Not the Same as Knowing Its Cause

The workers’ compensation judge had previously addressed section 5412 while rejecting a statute-of-limitations defense. The judge focused on testimony that Zeber learned in 2017 or 2018—after speaking with his son—that a former professional athlete might be able to file a California workers’ compensation claim.

The Court of Appeal found that reasoning insufficient to establish the section 5412 date for arbitration. Awareness that a legal claim may be available is different from knowledge that a disability was caused by employment. The record required a factual finding addressing the latter question.

Why the Court Could Not Set the Date Itself

The WCJ had never made an express section 5412 date-of-injury finding for purposes of section 5275. Because that date is a factual question and a prerequisite to mandatory arbitration, the WCAB exceeded its authority by sending the coverage dispute directly to arbitration.

The appellate court could not fill the gap by reviewing the record and selecting a date itself. Labor Code sections 5951 and 5953 limit judicial review of WCAB decisions and prevent the Court of Appeal from making new factual findings. Nor could the missing finding be treated as harmless, because the earlier analysis concerned knowledge of filing rights rather than knowledge of industrial causation.

The Decision Did Not Resolve Coverage or Benefits

The Court of Appeal annulled the WCAB’s decision and remanded the matter for a factual finding under section 5412. It did not decide whether the Yankees had Travelers coverage, whether arbitration ultimately would be required, or the final amount of benefits owed to Zeber.

The opinion was filed on May 7, 2025, and certified for publication on May 28, 2025. It remains published authority. On June 5, 2026, the WCAB issued a decision after remand returning the case to the trial level for an evidentiary hearing on the section 5412 date. The ultimate insurance-coverage forum therefore remained unresolved at that stage.

Practical Lessons for Cumulative-Trauma Claims

Travelers shows that “date of injury” can serve different functions across a workers’ compensation case, and the controlling statutory definition matters. The last day worked, the first day of symptoms, the date of disability, the date of causation knowledge, and the date the worker learns a claim is legally available may all be different.

Parties addressing cumulative trauma should develop evidence about both elements of section 5412: disability and knowledge of industrial causation. Medical records, communications with physicians, prior claims, employment history, and credible testimony may determine not only timeliness and benefit rates, but also whether an insurance dispute must be arbitrated.