Workers’ Compensation · Primary-source case analysis

Stevens: IMR Was Constitutional, but the WCAB Retained Limited Statutory Review

By Aneeta Mishra and Timothy Chan

Published April 19, 2026

Stevens separates the medical-necessity determination assigned to IMR from the WCAB's authority to correct an IMR decision made without statutory authority.

Treatment requests after permanent total disability

Frances Stevens developed complex regional pain syndrome after a work injury and was found permanently totally disabled. Her physician requested medications and a home health aide. Utilization review denied the requests, and IMR affirmed.

The constitutional challenges failed

The court held that the Legislature's plenary authority over workers' compensation permitted the IMR structure. The process did not violate separation of powers, the constitutional requirement of substantial justice and review, or federal due process because the worker could submit evidence and receive reasoned administrative review.

Medical necessity and legal authority differ

The WCAB generally cannot reweigh the anonymous physician's medical-necessity determination. But it may review whether the IMR determination was adopted without authority, including whether it categorically excluded home-health care from the statutory concept of medical treatment despite governing law.

Disposition

The court remanded for the Board to decide whether the home-health denial was unauthorized. The result did not convert the Board into a second medical reviewer; it preserved review of the decision's statutory boundary.

Key takeaways

• Distinguish medical disagreement from legal-authority error.
• IMR remains the forum for medical-necessity disputes.
• The WCAB may address specified statutory defects under section 4610.6(h).
• Preserve the treatment request, UR rationale, IMR record, and asserted review ground.