PROJECT SUMMARY To address the aims of the proposed research and RFA-HL-21-018, we will use a syndemics and multi-level approach to investigate relationships between sleep and HIV treatment outcomes and behaviors (e.g., viral suppression and retention in care) cross-sectionally and longitudinally among young people impacted by HIV followed over one year to inform interventions. We will enroll 250 men from the NIH-funded Neighborhoods and Networks (N2) Cohort Study in the proposed N2 Sleep Health Study to address the aims of the research. Eligibility requirements include HIV-seropositive and self-reported willingness to wear a wrist actigraph for 2 weeks at three points over the course of a year. In this longitudinal study, after completing the initial 2-week wrist actigraphy protocol, participants will carry the wrist actigraph for an additional 2 weeks every six months over the one-year study period—for a total of three times. Objectively measured sleep data at baseline could potentially influence decision-making regarding HIV treatment (e.g., antiretroviral treatment [ART] outcomes) over time, providing a clear temporal ordering and an ability to consider potential time-lags. Multi-level factors – e.g., individual-level obesity, intimate partner violence, and spatial proximity to healthcare services – may modify these relationships. The proposed study will be the first objective sleep health study among any population of men. Findings from the proposed research have significant implications for targeting contextually appropriate sleep and HIV interventions as there is a need for new approaches to inform the next generation of HIV interventions (i.e., long-acting injectables).