More than half of people living with HIV (PWH) in the United States (US) are 50 years of age or older. Compared with those without HIV, older PWH have 2.3-fold increased risk of depression. The impact of unmitigated mental health symptoms and related conditions among this growing population is significant and includes social isolation, loss of independence, and poor engagement with healthcare, undermining progress towards ending the HIV epidemic. Due to a shortage behavioral health providers, there is growing interest in innovative interventions using community-based, peer-led approaches to improve access to effective mental health services. Behavioral activation is an evidence-based intervention that has shown promise for reducing depressive symptoms among older adults. Our team has developed a streamlined lay-delivered behavioral activation intervention called “Do More, Feel Better” (DMFB) that has been shown to decrease depressive symptoms among depressed (PHQ-9 ≥10) older adults obtaining services in community senior centers. Delivery of an adapted version of the DMFB intervention for older PWH with poor access to professional counseling could be relatively straightforward within the existing Ryan White HIV/AIDS program, supported by organizations that provide essential services such as non-medical case management to low-income PWH. Because the intervention is tailored to individual preferences and needs, it promises to be acceptable, especially after careful adaptation using input from community members and stakeholders. Our aims for the proposed work are therefore: (1) to understand the impact of mental health issues on HIV care, functioning, and quality of life and identify multi-level barriers and facilitators that could influence participation in and delivery of an adapted DMFB intervention; (2) to adapt and enhance the DMFB intervention for delivery by case management program staff or volunteers to older PWH, following the ADAPT-ITT model in collaboration