Cal. HSC § 1649.6

(a) If a federal regulatory agency, the United States Department of Justice (US DOJ), or the federal Centers for Medicare and Medicaid Services (CMS) takes one of the following actions, or makes an inquiry about the health care facility’s activities pursuant to Section 1649.2, a health care facility may suspend compliance with Section 1649.2 until the regulatory agency, the US DOJ, or CMS notifies the health care facility that it may resume permitting the use of medicinal cannabis within the facility:

(1) A federal regulatory agency or the US DOJ initiates enforcement action, including a notice to suspend funding, against a health care facility related to the facility’s compliance with a state-regulated medical marijuana program.

(2) A federal regulatory agency, the US DOJ, or CMS issues a rule, guidance, or otherwise provides notification to the health care facility that expressly prohibits the use of medical marijuana in health care facilities or otherwise prohibits compliance with a state-regulated medical marijuana program.

(b) This section does not permit a health care facility to prohibit patient use of medicinal cannabis due solely to the fact that cannabis is a Schedule I drug pursuant to the federal Uniform Controlled Substances Act, or other federal constraints on the use of medicinal cannabis that were in existence prior to the enactment of this chapter.