Existing law, the Mental Health Services Act (MHSA) , an initiative measure enacted by the voters as Proposition 63 at the November 2, 2004, statewide general election, funds a system of county mental health plans for the provision of mental health services, as specified. The MHSA establishes the Mental Health Services Fund, a continuously appropriated fund, which is administered by the State Department of Health Care Services (department) , to fund specified county mental health programs. Existing law, the Behavioral Health Services Act (BHSA) , a legislative act amending the MHSA that was approved by the voters as Proposition 1 at the March 5, 2024, statewide primary election, recast the MHSA by, among other things, renaming the fund to the Behavioral Health Services Fund and reallocating how moneys from that fund may be spent. The BHSA requires each county to establish and administer a full-service partnership program that includes, among other things, outpatient behavioral health services, as specified, and housing interventions. This bill would establish criteria for an individual with a serious mental illness to be presumptively eligible for a full-service partnership, including, among other things, the person is transitioning to the community after 6 months or more in the state prison or county jail. The bill would specify that a county is not required to enroll an individual who meets that presumptive eligibility criteria if doing so would conflict with contractual Medi-Cal obligations or court orders, or exceed full-service partnership capacity or funding, as specified. The bill would make enrollment of a presumptively eligible individual contingent upon the individual meeting specified criteria and receiving a recommendation for enrollment by a licensed behavioral health clinician, as specified. The bill would prohibit deeming an individual with a serious mental illness ineligible for enrollment in a full-service partnership solely because their primary diagnosis is a substance use disorder. The bill would make these provisions operative on January 1, 2027.