Special Projects of National Significance - Cooperative Agreements - In response to HRSA-25-059, Improving Mental Health and Engagement in Care Among People with HIV—Evaluation Provider (EP), JSI and University of Massachusetts, Lowell (UML) are partnering to advance the selection, evaluation, and dissemination of interventions for engaging and retaining people with co-occurring HIV and mental health conditions. The EP will work collaboratively with the Implementation and Technical Assistance Provider (ITAP), funded under HRSA-25-058, to achieve the initiative objectives: 1. Support a national cohort of implementation sites to adapt and implement responsive interventions to engage and retain people with co-occurring HIV and mental health conditions in HIV primary care and mental health services. 2. Evaluate the implementation of interventions using implementation science frameworks, including documenting and sharing evaluation findings throughout the initiative to support successful implementation. 3. Create and disseminate user-friendly multimedia materials to help other RWHAP organizations replicate effective interventions. We will leverage our extensive experience related to HIV service delivery, mental health, multisite evaluation (MSE) and implementation science, and dissemination of findings. We will also engage people with lived experience and subject matter experts through the proposed Evaluation Advisory Board to guide the project. JSI will collaborate with the ITAP to identify and select emerging, evidence-informed, and evidence-based interventions to engage and retain people with HIV and co-occurring mental health conditions in care. We will provide comprehensive evaluation-related information and insight during the site selection process. JSI and UML will conduct a MSE grounded in the HRSA HAB implementation science (HAB IS) approach to evaluate interventions that better serve people with co-occurring HIV and mental health conditions. The MSE will employ a mixed-methods strategy to assess implementation, including documenting adaptations, facilitators and barriers, cost, and outcomes. JSI proposes the following MSE questions guided by HAB IS and the Proctor Model, aimed at understanding what works and why for implementation, service, and client outcomes: 1. To what extent did the sites increase their capacity to implement interventions to engage and retain people with co-occurring HIV and mental health conditions? 2. What are the costs associated with implementing interventions to engage and retain people with co-occurring HIV and mental health conditions? 3. To what extent did the interventions engage and retain people with co-occurring HIV and mental health conditions? 4. To what extent did the interventions improve client health outcomes for people with co-occurring HIV and mental health conditions? JSI will engage implementation sites in evaluation activities and provide evaluation technical assistance. We will work with the sites to develop a site-specific evaluation plan and logic model to illustrate the intervention, implementation strategies, and outcomes. JSI will collaborate with the ITAP and HRSA HAB to develop standardized measurement tools, analysis plans, and a digital data collection and reporting system. This will include capturing information for the cost analysis led by UML, as well as collecting data on implementation, service, and client outcomes through provider interviews, monthly implementation reports, client surveys, chart abstraction, and site-selected qualitative methodology. To support dissemination, JSI will contribute to the initiative communications and dissemination plan, participate in the Publication and Dissemination Committee, and prepare dissemination products. We will partner with the ITAP to create a joint work plan and align dissemination efforts to promote and replicate interventions for engaging and retaining people with co-occurring HIV and mental health conditions within the RWHAP community.