Workers’ Compensation · Primary-source case analysis

McDuffie: How the WCAB Should Develop an Incomplete Medical Record

By Aneeta Mishra and Timothy Chan

Published September 13, 2026

McDuffie v. Los Angeles County Metropolitan Transit Authority establishes an orderly sequence for developing medical evidence after trial or submission when the existing record cannot support a decision.

The record did not adequately resolve disability

The workers’ compensation judge found the medical record inadequate on permanent disability and appointed a new medical evaluator. The defendant challenged that appointment, arguing that the parties’ existing medical evaluators should be asked to address the identified gaps.

Existing physicians come first

The Board held that the preferred first step is to obtain supplemental reports or depositions from physicians who have already reported. This respects the parties’ evaluator selections and focuses development on the specific deficiencies already identified.

An AME or appointed examiner is a later step

If existing doctors are unavailable, lack the needed expertise, or cannot cure the record, the parties may consider an agreed medical evaluator. Only if those routes fail or are impracticable should the judge or Board appoint another physician.

The appointment was rescinded

The WCAB rescinded the new examiner’s appointment and returned the matter for supplemental development from the existing doctors. McDuffie authorizes development of the record but discourages bypassing the established medical process without good cause.

Key takeaways

• Identify the precise medical question the record fails to answer.
• Seek targeted supplementation from existing evaluators first.
• Document good cause before moving to a new examiner.
• Keep the development process tied to the disputed issues.