Cal. Welf. & Inst. Code § 5349

(a) A county or group of counties that does not wish to implement this article may opt out of the requirements of this article by a resolution passed by the governing body that state the reasons for opting out and any facts or circumstances relied on in making that decision. To the extent otherwise permitted under state and federal law, counties that implement this article may pay for the provision of services under Sections 5347 and 5348 using funds distributed to the counties from the Mental Health Subaccount, the Mental Health Equity Subaccount, and the Vehicle License Collection Account of the Local Revenue Fund, funds from the Mental Health Account and the Behavioral Health Subaccount within the Support Services Account of the Local Revenue Fund 2011, funds from the Behavioral Health Services Fund when included in county plans pursuant to Section 5847, and any other funds from which the Controller makes distributions to the counties for those purposes. Compliance with this section shall be monitored by the State Department of Health Care Services as part of the review and approval of city, county, or group of county performance contracts.
(b) In lieu of the resolution to opt out pursuant to subdivision (a), a county may elect to implement this article in combination with one or more counties pursuant to the implementation provisions of subdivision (d).
(c) A county or group of counties implementing this article shall not reduce existing voluntary mental health programs serving adults or children’s mental health programs as a result of implementation.
(d) If multiple counties choose to provide services pursuant to Section 5348, those counties shall execute a memorandum of understanding (MOU) that shall include, but not be limited to, a process for designating the lead county for an individual receiving services pursuant to the MOU for the following purposes:
1. (1) Making the finding set forth in subdivision (d) of Section 5346.
2. (2) Ensuring that services are provided and determining where they are provided.
3. (3) Determining the county incurring financial responsibility, as applicable, for an individual receiving services.
4. (4) Ensuring that appropriate followup care is in place upon an individual’s release from the treatment program.
(e) This section shall become operative on July 1, 2021.