Planning for Implementation of a Family-based Intervention for Prevention of HIV, Substance Use, and Mental Health Problems among Hispanic Youth at Risk: A Community-Engaged Approach - Hispanic youth at risk face disparities in HIV, substance use, and mental health non-Hispanic peers. Family-based interventions are effective in preventing and reducing HIV acquisition, substance use, and mental health concerns. Our team developed Familias con Orgullo (“Families with Pride”), a family-based intervention to prevent HIV, substance use, and mental health problems among Hispanic youth at risk. Despite the promise of Familias con Orgullo, there are anticipatable challenges to implementing Familias con Orgullo in community settings given commonly cited barriers such as inadequate time and resources by staff. However, it is unclear what specific implementation strategies would facilitate adoption and implementation of Familias con Orgullo. The purpose of the proposed study is to co-design an implementation strategy package iteratively in collaboration with community agencies across Miami-Dade County using a systematic implementer-driven method to inform the future adoption and implementation of Familias con Orgullo. The aims of the study are: AIM 1: identify determinants affecting adoption and implementation of behavioral HIV prevention interventions, such as Familias con Orgullo, in community agencies, AIM 2: iteratively co-design an implementation strategy package to support community agencies in adopting and implementing Familias con Orgullo, and AIM 3: evaluate the relative priority, acceptability, appropriateness, and feasibility of the implementation strategy package for promoting adoption and implementation of Familias con Orgullo. The proposed research aims complement my training goals to: Training Goal 1: develop advanced skills in implementation science for prevention of HIV, substance use, and mental health problems among Hispanic youth at risk, Training Goal 2: develop expertise in community-engaged methods to develop implementation strategies and conduct implementation research, Training Goal 3: build skills in syndemic theory to address HIV, substance use, and mental health problems, and Training Goal 4: expand my professional development training. Successful completion of these aims will enable me, as part of a future R01, to test the impact of developed implementation strategies on adoption and implementation of Familias con Orgullo in community settings in addition to evaluating the effectiveness of Familias con Orgullo. My long-term goal is to become an independent researcher focused on using implementation science to mitigate HIV, substance use, and mental health disparities among Hispanic youth at risk. With a mentorship of a team of interdisciplinary researchers, experts in implementation science, implementation research methodology, behavioral HIV-prevention, and family-based interventions, I will successfully complete the planned research and training aims proposed in this career development award at the University of Miami, resulting in a solid foundation for me to launch my career as an independent researcher.