PROJECT SUMMARY/ABSTRACT The 1.7 million adolescents living with HIV (ALHIV) globally urgently need interventions to help improve retention, adherence, and ultimately viral load suppression (VLS). With both high rates of incident infection and some of the lowest VLS rates, ALHIV experience high mortality with approximately 100 deaths per day. Successful interventions to improve retention and VLS among ALHIV in low- and middle-income countries (LMIC) remain limited. Video-based interventions that provide counseling to patients living with HIV have increased patient HIV knowledge, supported disclosure, fostered behavior change, and improved treatment adherence. Targeted messaging can be woven into culturally relevant films with engaging storylines and delivered at critical teachable moments. Films can be shown in high-volume clinics to deliver standardized counseling content while freeing up HCW time. While video-based interventions have the potential to address barriers to ALHIV ART retention and adherence, they are not commonly used throughout Sub-Saharan Africa (SSA). Our team was one of the first to pilot and study the impact of a video-based intervention on HIV service delivery; preliminary results have suggested high levels of patient and HCW satisfaction, improved ART knowledge, adherence, and retention. Based on these promising results, we propose to adapt, assess and support scale up of a tailored, video-based counseling package for ALHIV: VITAL (Video Intervention to Inspire Treatment Adherence for Life) Start for Adolescents (VS4A). Our study will examine the impact of VS4A on the primary composite outcome of retention and adherence (viral load <1000 copies/ml) in a multisite two-arm cluster randomized controlled trial (CRCT) with 1:1 randomization in Malawi. Our overall hypothesis is that VS4A will a) achieve broad reach, b) be acceptable and feasible to implement, c) improve adolescent VLS and several secondary outcomes; and d) be cost-effective at scale. If effective, VS4A can be an innovative, scalable tool to improve service delivery for ALHIV while also liberating HCW time and reducing health system burden in Malawi. Building on a 15-year partnership with the Malawi Ministry of Health (MOH), a track record of excellence and innovation in service to ALHIV, and a robust implementation science research portfolio, our team is poised to successfully implement the VS4A study and program and to use findings to support rapid, wide-scale dissemination and scale up.