Workers’ Compensation · Primary-source case analysis

Virginia Sanchez: Prior Awards and Overlapping Permanent Disability

By Aneeta Mishra and Timothy Chan

Published April 30, 2026

Decision: Sanchez v. Cnty. of Los Angeles, No. MON 0307506 (WCAB Oct. 26, 2005) (en banc).

Virginia Sanchez sets the section 4664 framework for apportioning a new award when an earlier award concerns the same body region.

A foot injury followed a prior knee award

The worker had a stipulated 22 percent award for bilateral knees and later sustained a left-foot injury rated at seven percent. The dispute was whether the disabilities overlapped.

The defendant must prove the prior award

Once the employer establishes a prior award involving the same body region, section 4664 conclusively presumes the underlying permanent disability still exists. Medical rehabilitation cannot defeat that presumption.

The worker may disprove overlap

The prior percentage is subtracted from current overall disability unless the worker shows that the earlier and current disabilities affect different earning capacities, in whole or part.

Disposition

The Board announced the overlap rules and the 100-percent regional ceiling, then applied them to the record. The analysis requires the actual basis of both ratings.

Key takeaways

• Obtain the prior award and rating formula.
• Identify the body region and disability factors.
• Place the burden of proving the award on the defendant.
• Develop evidence disproving overlap where appropriate.