This policy brief summarizes findings from the first study to evaluate how California's public mental health delivery system has served older adults (60 years of age and over) since the passage of the Mental Health Services Act (MHSA) in 2004. Study findings indicate that there are unmet needs among older adults with mental illness in the public mental health delivery system. There are deficits in the involvement of older adults in the required MHSA planning processes and in outreach and service delivery, workforce development, and outcomes measurement and reporting. There is also evidence of promising programs and strategies that counties have advanced to address these deficits. Recommendations for improving mental health services for older adults include designating a distinct administrative and leadership structure for older adult services in each county; enhancing older adult outreach and documentation of unmet need; promoting standardized geriatric training of providers; instituting standardized data-reporting requirements; and increasing service integration efforts, especially between medical, behavioral health, aging, and substance use disorder services.