New California Law Increases Maximum Physician-to-PA Supervision Ratio from 1:4 to 1:8 as of January 1, 2026

Assembly Bill No. 1501 (AB 1501) was signed by Governor Gavin Newsom on October 1, 2025, and went into effect on January 1, 2026. The bill made a number of amendments to the state’s Physician Assistant Practice Act, which is the set of laws regulating PAs’ licensure and practice.

Most significantly, AB 1501 increased the maximum number of PAs that a physician may supervise at any one time from four to eight [1]. Previously, the 1:8 ratio was only permitted for PAs performing in-home health evaluations—a narrow exception that was added in 2024 (though the PA supervision requirement was waived entirely for three years during the state’s COVID-19 state of emergency). Now, the 1:8 ratio is permitted in all practice settings. The other provisions regarding PA supervision have not changed. For example, the statutes still provide an exception from the supervision requirements during a declared emergency, and a supervising physician is still required to hold a current, unrestricted license and be available to the PA for consultation.

Note that an increase in the legally permitted supervision ratio to 1:8 does not obligate organizations to adopt this maximum threshold. Organizations should assess whether modifying their internal supervision policies is appropriate for their clinical environment. While expanding the supervision ratio may introduce heightened risk to patient safety by potentially limiting the availability and oversight capacity of supervising physicians, it may also be beneficial in settings where physician resources are limited. Moreover, payers may have supervision requirements that are more stringent than state law, so organizations that decide to expand their internal supervision ratio should verify compliance with relevant payer requirements.

AB 1501 also directed the Physician Assistant Board (PAB), in collaboration with other stakeholders, to conduct “a comprehensive review of practice agreement structures.”[2] The review will “consider how practice agreements are utilized in other states” and “evaluate their potential benefits or detriments to patient care, workforce efficiency, and regulatory oversight.” One of the goals of the review is to “inform future policy discussions,” which suggests that the PAB’s findings may prompt the Legislature to consider changes to practice agreement requirements.

In light of AB 1501’s changes, we recommend the following:

• Discuss with your organization’s risk management or legal team the potential advantages and disadvantages of increasing the internal supervision ratio for your organization’s PAs.
• Review your organization’s governing documents (such as the medical staff’s bylaws, rules and regulations, and policies and procedures) and PA practice agreements to see if any changes are needed or desired given the increased supervision ratio.
• Educate your organization’s clinical leaders, physicians, and PAs regarding the increased supervision ratio.
• If your organization decides to implement an increased supervision ratio, confirm that the new ratio complies with relevant payers’ PA supervision requirements.
• Monitor updates from the PAB about its review of PA practice agreement structures and potential changes to the requirements for these agreements.

[1] Business and Professions Code, section 3516, subd. (b).
[2] Business and Professions Code section 3502.35