Cal. Health & Saf. Code § 11217
Except as provided in Section 11223, no person shall treat a person with substance use disorder for addiction to a narcotic drug except in one of the following:
A narcotic controlled substance in the continuing treatment of addiction to a controlled substance shall be used only in those programs licensed by the State Department of Health Care Services pursuant to Article 1 (commencing with Section 11839) of Chapter 10 of Part 2 of Division 10.5 on either an inpatient or outpatient basis, or both.
This section does not apply during emergency treatment, or where the patient's addiction is complicated by the presence of incurable disease, serious accident, or injury, or the infirmities of old age.
Neither this section nor any other provision of this division shall be construed to prohibit the maintenance of a place in which persons seeking to recover from addiction to a controlled substance reside and endeavor to aid one another and receive aid from others in recovering from that addiction, nor does this section or this division prohibit that aid, provided that no person is treated for addiction in a place by means of administering, furnishing, or prescribing of controlled substances. The preceding sentence is declaratory of preexisting law.
Neither this section or any other provision of this division shall be construed to prohibit short-term narcotic detoxification treatment in a controlled setting approved by the director and pursuant to rules and regulations of the director. Facilities and treatment approved by the director under this paragraph shall not be subject to approval or inspection by the Medical Board of California, nor shall persons in those facilities be required to register with, or report the termination of residence with, the police department or sheriff's office.
Ca. Health and Saf. Code § 11217