This FOA encourages exploratory/developmental research applications at the intersection of HIV and aging by addressing two overarching objectives: 1) to improve understanding of biological, clinical, and socio-behavioral aspects of aging through the lens of HIV infection and its treatment; and 2) to improve approaches for testing, prevention, and treatment of HIV infection, and management of HIV-related comorbidities, co-infections, and complications in different populations and cultural settings by applying our current understanding of aging science.