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 significant disparities in HIV, accounting for 31% of new HIV diagnoses among youth ages 13-24 in the US, as well as disproportionately high rates of substance use and mental health problems compared to their non-Hispanic peers. These interconnected health challenges contribute substantially to adverse health outcomes, highlighting the need for practical, scalable solutions that improve access to effective behavioral HIV preventive interventions that can reduce those disparities. Family-based interventions are effective in preventing and reducing HIV acquisition, substance use, and mental health concerns. Our team developed 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 Families with Pride, there are anticipatable challenges to implementing Families with Pride in community settings given commonly cited barriers to efficient implementation. However, it is unclear what specific implementation strategies would facilitate adoption and implementation of Families with Pride. This project takes a solutions-oriented approach to addressing HIV and related behavioral health disparities among Hispanic youth at risk by identifying implementation determinants and co-designing actionable strategies to support the successful delivery of behavioral HIV preventive interventions in community settings. 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 Families with Pride. The aims of the study are: AIM 1: identify determinants affecting adoption and implementation of behavioral HIV prevention interventions, such as Families with Pride, in community agencies, AIM 2: iteratively co-design an implementation strategy package to support community agencies in adopting and implementing Families with Pride, and AIM 3: evaluate the relative priority, acceptability, appropriateness, and feasibility of the implementation strategy package for promoting adoption and implementation of Families with Pride. 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, 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 Families with Pride in community settings in addition to evaluating the intervention’s effectiveness. 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.