Integration of Trusted Adult Supports into the HealthMpowerment App to Improve Black Adolescent and Young Adult PrEP Use - Through lived experiences and my position as an adolescent medicine physician, I have witnessed the lifelong consequences that disparities in health outcomes impose on vulnerable adolescents and young adults (AYAs). This has fueled my long-term goal of developing interventions that empower AYAs, providers, and adults who support AYA acquisition of skills that positively impact all aspects of sexual health, including HIV prevention. Pre-exposure prophylaxis (PrEP) for HIV, a daily or intermittently dosed oral pill, has been shown to be a highly effective biomedical tool for preventing HIV infection. However, the benefits of PrEP have not been experienced equally among all populations with HIV acquisition risk. In particular, PrEP use and adherence rates are low among Blacks, especially Black adolescents and young adults (AYAs), which may explain the disproportionate rates of HIV in many Black communities. Although there are many barriers to PrEP use and adherence among Blacks, including low perception of risk; challenges adhering to a pill regimen and visit schedule; and HIV- and sex-related stigma, few solutions have been shown to improve PrEP use in this population, especially among Black AYAs. An intervention that increases PrEP adherence may be of particular importance for Black AYAs in the Deep South, particularly in states such as Alabama, which has been named a geographic hotspot in the Department of Health and Human Service’s Ending the HIV Epidemic 10-year plan. Grounded in Social Cognitive Theory, and building on previously published data, this proposed study will integrate AYA-trusted adult social support dyadic communication with an existing mobile Health (mHealth) app–the HealthMpowerment app–to facilitate increased PrEP use and adherence among Black AYAs in the Deep South. As more than half of new HIV infections in Alabama occur in rural communities, we will collaborate with community partners within urban and rural areas and create two community advisory boards, one with Black AYAs and one with adults providing support to Black AYAs, to ensure this app fits the needs of urban and rural Black AYAs. Specifically, this multi- methods study will use qualitative interviews and discrete choice experiment surveys to identify 1) trusted adults Black AYAs would ideally partner with, 2) what information trusted adult supports would need to support Black AYAs in PrEP adherence, and 3) app features that Black AYAs and their trusted adult supports feel would best support dyadic communication around AYA PrEP use. After adaptation, the app will be piloted by Black AYAs 14 to 21 years old to inform an application for R34 funding of a larger pilot study. If validated in future clinical trials, this intervention could prove helpful in alleviating disparities in HIV incidence. In addition to providing a tailored health intervention, the comprehensive experiential training, expert mentorship and advising, and critical didactic coursework embodied in this rigorous proposal will build on my clinical expertise and strong background building community partnerships and provide the additional skills I need to become a leader in the development of health behavior interventions focused on reducing disparities in sexual and reproductive health outcomes.