Project Summary/Abstract Youth living with HIV (YLHIV) are at the forefront of the HIV epidemic globally, as more perinatally infected children increasingly survive into adulthood, and more youth become infected worldwide. HIV-related stigma is a critical challenge to antiretroviral therapy (ART) adherence and retention in care of YLHIV and is associated with mental health issues such as depression and anxiety. Few stigma-reduction strategies exist for youth, however, particularly in low and middle income countries (LMICs). The overall goals of the proposed research are to deepen understanding of the spectrum of stigma experienced by YLHIV in Vietnam and to identify relevant mediation strategies. Our Specific Aims (SA) are to 1) adapt a psychosocial stigma-reduction intervention for YLHIV in Vietnam based on cognitive-behavioral therapy (CBT) principles and delivered by telephone, using critical input from youth during intervention development; 2) assess the feasibility, acceptability and preliminary efficacy of this innovative approach to reduce stigma, and improve psychosocial wellbeing and ART adherence among YLHIV through a small pre-post study; 3) explore the multiple facets of stigma experienced by YLHIV in Vietnam and their relationships with ART adherence and psychosocial wellbeing via quantitative surveys and electronic adherence monitoring; and 4) strengthen our team's capacity to conduct future research on stigma and stigma-reduction interventions. The research will be conducted over two years in three phases. Phase 1 will comprise intervention development including initial interviews with YLHIV and pilot testing to meet SA1. In Phase 2, the intervention will be provided remotely to 40 YLHIV accessing HIV care at outpatient clinics in Hanoi; sociodemographic, psychosocial, and clinical data will be collected at baseline and endline, and adherence will be monitored continuously via wireless pill containers. Phase 3 will involve data analysis and dissemination activities. Our proposed intervention will target multiple levels of stigma experienced by YLHIV using supportive self-management skills; it is grounded in CBT principles and in previous research which has documented interrelationships among stigma, psychosocial wellbeing, and ART adherence. The core psychosocial treatment plan will comprise four months of weekly coaching sessions by phone, followed by two monthly ?booster? sessions, and will be tailored to the situation of each participant. Analysis of baseline, endline, and the continuous adherence data will enable the achievement of SA2 and SA3 and thereby contribute to the scientific evidence base on low-cost strategies to reduce stigma and improve psychosocial wellbeing and ART adherence for YLHIV in LMICs. The study's team of experienced multi-disciplinary Vietnamese and American researchers has exceptional capacity to conduct the study; our close collaboration supplemented by skill-specific training throughout the project will help us to strengthen our capacity to conduct future work on stigma and psychosocial interventions, thus addressing SA4. With strong support from Vietnamese officials and clinicians, as well as international experts, our results have high potential for policy and program impact.