Cal. Business and Professions Code § 4980.43.4

(a) A trainee, associate, or applicant for licensure shall only perform mental health and related services at the places where their employer permits business to be conducted. (b) An associate who is employed by or is volunteering in a private practice or a professional corporation shall be supervised by an individual who is both of the following: (1) Is employed by or contracted by the associate’s employer or is an owner of the private practice or professional corporation. (2) Either provides psychotherapeutic services to clients for the associate’s employer, or meets both of the following: (A) The supervisor and the associate’s employer have a written contract providing the supervisor the same access to the associate’s clinical records provided to employees of that employer. (B) The associate’s clients authorize the release of their clinical records to the supervisor. (c) At any one time, supervisors in nonexempt settings shall not serve as individual or triadic supervisors for more than a total of six persons who are not fully licensed at the highest level for independent clinical practice and who are receiving supervision for providing clinical mental health services in a nonexempt setting. (d) A written oversight agreement, as specified by the board by regulation, shall be executed between the supervisor and employer when the supervisor is not employed by the supervisee’s employer or is a volunteer. The supervisor shall evaluate the site or sites where the supervisee will be gaining experience to determine that the site or sites comply with the requirements of this chapter.