UPROJECT ABSTRACT/ SUMMARY Adolescents are at the core of the global HIV epidemic. They are highly vulnerable to HIV acquisition and—for adolescents living with HIV (ALHIV)—at disproportionate risk for poor health outcomes across the HIV care continuum. Retention rates, adherence to antiretroviral treatment (ART), and viral suppression (VS) are alarmingly low among ALHIV, warranting urgent attention. Adolescence is a time of rapid physical and psychological development, when youth move from childhood to adulthood and experience multiple challenges as well as opportunities for growth, creativity, and learning. Youth who enter this period under adverse conditions are ill prepared to cope with the impact of living with a potentially fatal, stigmatized, transmissible infection and the need to adopt positive, health-seeking behaviors, engage with health services, and adhere to daily ART regimens. In high prevalence countries like Mozambique, the burden of living with HIV during this vulnerable developmental stage is further exacerbated by fragile health systems and nascent ALHIV-specific differentiated service delivery (DSD) models. At the same time, few specific interventions have been developed and tested that address the needs of ALHIV. In response, we propose to develop and test a culturally- appropriate, contextually-relevant, and theoretically-grounded adolescent-focused multicomponent intervention strategy, CombinADO, among ALHIV in Zambézia, Mozambique. Using a human- centered design approach, we will work with ALHIV, caregivers, health care providers, and local and national stakeholders to develop and pilot this CombinADO intervention strategy consisting of four components: 1) ALHIV peer navigation and support, 2) adolescent-friendly services, 3) mHealth technologies, and 4) health communication messaging (Phase 1). In Phase 2, we propose to evaluate the effectiveness of the CombinADO strategy on three milestones along the HIV care continuum: (a) retention in HIV care, (b) ART adherence, and (c) VS among ALHIV using a cluster randomized controlled trial design. The study builds on longstanding partnerships between ICAP at Columbia University, the Mozambique Ministry of Health and other local stakeholders, all aiming to improve the disease course as well as outcomes along the continuum of care for this highly vulnerable population, adolescents living with HIV.