Project Summary/Abstract To achieve aspirational goals to end the HIV epidemic (EHE), evidence-based practices (EBPs) to increase viral suppression must be implemented effectively nationally. The Managed Problem Solving (MAPS) behavioral intervention is an EBP for behavior change in people living with HIV (PLWH). To accomplish the goals of this application, we leverage a data-to-care partnership between the Philadelphia Department of Public Health (PDPH) and participating clinics (n = 12), which enhances the sustainability of our approach. We propose that MAPS can be delivered by trained Community Health Workers (CHWs). The use of CHWs to deliver MAPS is justified by their ability to develop trusting relationships with their clients and the need for task shifting in busy clinics. In order to also address retention in care, we will adapt MAPS to also focus on problem solving activities tailored toward retention in care (now termed MAPS+). CHWs will be located in clinics to implement MAPS+ to improve viral suppression and care retention in PLWH. Data-to-care allows for identification of people who are lost to care and link these patients back to care. Currently, medication adherence and retention in HIV care are not targeted in data-to-care so we will build on this approach to facilitate the identification of PLWH who are out of care and not virally suppressed to offer them MAPS+. Our set of implementation strategies include task- shifting the delivery of MAPS+ to CHWs, providing the CHWs training and ongoing support, and increasing communication between the CHWs and medical care team via standardized protocols. We will conduct a hybrid type II effectiveness-implementation trial with a stepped-wedge cluster randomized design in 12 clinics to test MAPS+ compared to usual care using a set of implementation strategies that we believe will best support implementation. Each clinic will be randomized to one of three implementation start times. We will collect baseline (usual care) data from each clinic for 6 months, followed by MAPS+ and our package of implementation strategies for 12 months, in three cohorts of 4 clinics each. Aim 1 will test the effectiveness of MAPS+ on clinical effectiveness outcomes, including viral suppression (primary) and retention (secondary). Aim 2 will examine the effect of the package of implementation strategies on reach. We will also measure implementation cost. Aim 3 will apply a qualitative approach to understand processes, mechanisms, and sustainment of our implementation approach. Our results will guide future efforts to implement behavioral EBPs across the HIV care continuum, consistent with the “treat” pillar of EHE, and move the science of implementation services, consistent with NIH strategic priorities.