Effective January 1, 2026, a new law — Assembly Bill 1501 — will amend Section 3516 of the California Business and Professions Code to allow physicians to supervise up to eight physician assistants (PAs) at any one time in all health care settings. Currently, the law permits a 1:8 ratio only when PAs are conducting in-home evaluations. The current allowable supervising-physician-to-physician-assistant ratio is 1:4 in all other settings. The new law will allow a 1:8 ratio in any health care environment.

For many health facilities facing physician shortages and resource constraints, this change recognizes — to quote a new statement of purpose also included in AB 1501 — “the vital role physician assistants play in delivering safe, effective, and accessible health care across California” and will be welcome news. However, the expansion also presents new oversight challenges. Health facilities remain responsible for ensuring that only competent and qualified practitioners provide patient care.

Facilities choosing to allow physicians to supervise more PAs starting in 2026 should review and update their delineation of privileges and applicable rules, policies, and protocols regarding PA supervision consistent with the new law. Supervising physicians and PAs may need to examine and update their practice agreements to reflect higher supervision ratios. Supervising physicians and PAs should also confirm that any changes in supervision arrangements are reflected in their professional liability insurance coverage

Importantly, while the new 1:8 ratio is permitted, it is not required. For certain specialties or practice environments, maintaining the existing 1:4 ratio may remain appropriate until sufficient safeguards and support systems are in place.