Modified Project Summary/Abstract Section The drug crisis and ongoing HIV transmission in underserved parts of the U.S. has ignited a new focus on advancing unequal health outcomes, including HIV outcomes, in people who use substances. The UAB CFAR Substance Use Scientific Working Group (SWG) was launched in 2022 with the overall objective of building a community-engaged group of scientists and community members dedicated to ending HIV outcomes imbalances among people with substance use disorders. The SWG was developed to catalyze emerging investigators, research activities, and partnerships aimed at substance-using populations affected by HIV. The rationale for the SWG is that HIV continues to disproportionately impact people who use substances, specifically underserved populations in Alabama and across the globe.1-4 Indeed, these marginalized groups have not experienced the individual and population-level benefits of HIV prevention and treatment.5-7 At UAB, numerous investigators conduct substance use and HIV research, including those with established independent research portfolios who are attracting new trainees to UAB. They desire opportunities to network with one another around an HIV research agenda and collaborative opportunities to advance their work and obtain more impactful funding. In first year of the SWG, SWG members met regularly to conduct a needs assessment of substance use and HIV research from the perspective of trainees, fellows, and faculty. We identified opportunities to leverage clinical populations and emerging investigators to successfully compete for extramural funding and advance science. In the next cycle of CFAR funding, the SWG will achieve on the following specific aims: Aim 1. Develop scientists from a broad range of backgrounds with expertise in SUD and HIV research by facilitating structured training opportunities. Aim 2. Promote collaboration between experts in HIV, SUD, and research focused on improving access, outcomes, and well-being across populations by organizing and hosting annual symposia highlighting innovative research and enabling collaborations. Aim 3. Foster community partnerships to support SUD and HIV research by integrating an engaged community with expertise in SUD and HIV into research activities. The SWG will enable the UAB CFAR to make meaningful research contributions in HIV prevention and treatment in people who use drugs through the development of new investigators, collaborations, and partnerships. The expected outcome is a robust scientific community that works closely with community partners to compete for extramural funding, engage substance-using populations for research, and accelerate progress towards ending the HIV epidemic.