OVERALL ABSTRACT The proposed University of Washington (UW) Developmental AIDS Research Center (D-ARC) responds to the global HIV epidemic at a critical stage. Though more than 21 million people around the world receive antiretroviral therapy, the most marginalized populations continue to experience high incidence, less access to effective prevention and care, and greater mortality. Unmet needs persist in high-prevalence countries as well as “geographic hotspots” in the US such as Seattle's King County. Intersecting stigma, trauma, poverty, and substance abuse increase risk for mental illnesses, yet the effective treatments available are rarely implemented. The proposed D-ARC aims to address these challenges by catalyzing research that helps end the epidemic, with a focus on integrating care for mental disorders into HIV prevention and treatment strategies. Furthermore, Center investigators will support and apply the science of dissemination and implementation, with the overall goal of bringing such interventions to scale. The D-ARC aims to fill a gap in HIV behavioral science research at UW by capitalizing on the considerable strengths of UW's HIV expertise and bridging this with UW's longstanding leadership in the development and delivery of models of integrated mental health care. By combining UW expertise in (a) HIV research and (b) mental health care—now siloed geographically, programmatically, and conceptually—the Center will be a synergistic force capable of realizing is mission of Implementing Innovative Impactful Integrated Interventions. The proposed infrastructure capitalizes on the strengths of local expertise and broad ties with global collaborative networks, adding value to UW through the Center's administration, research support, and training missions, buttressed through additional institutional commitments of $762,296. Cross-cutting themes of the D-ARC are (a) leveraging local and global bidirectional pathways to learning and innovation by engaging communities of providers and (b) addressing inequities by testing research solutions that reduce disparities. Four proposed Cores address the Overall specific aims: 1) Catalyze and support innovative and impactful research to curb the HIV epidemic, with a focus on integrated intervention strategies (Administrative Core); 2) Provide needed technical assistance and training on research design, measurement, theory and novel statistical methods relevant to mental health and HIV research (Methods Core); 3) Stimulate practice-based research that promotes effective integrated mental health services in HIV care settings and disseminate findings broadly (Integrated Care Core); and 4) Nurture the Next Generation of diverse, multidisciplinary HIV researchers through training and innovative mentorship of early stage investigators and mentors (Developmental Core).