The Substance Abuse and Mental Health Services Administration (SAMHSA) and Administration on Aging (AoA) commissioned a series of Issue Briefs to address behavioral health issues that are important to older Americans. The Issue Briefs identify key information and opportunities for action that can improve the lives of older people. This Issue Brief identifies strategies to reach and engage diverse older adult populations in prevention services and early interventions to address behavioral health concerns. This Issue Brief: (1) Describes the prevalence of behavioral health problems in diverse groups of older adults; (2) Identifies strategies for reaching and engaging older adults in behavioral health services; (3) Discusses the delivery of culturally appropriate behavioral health services; and (4) Offers examples of behavioral health programs that have successfully engaged diverse groups of older adults, including African American, American Indian/Alaska Native (AI/AN), Asian American, and Hispanic/Latino older adults; lesbian, gay, bisexual, and transgender(LGBT) older populations; and older adults living in rural areas to learn about critical behavioral health conditions and problems affecting older adults, including prescription medication misuse and abuse, suicide, depression, and anxiety and evidence-based prevention and treatment programs to address these problems.