0BPROJECT SUMMARY/ABSTRACT Zambia has one of the highest incidences of HIV in the world, and adolescent girls and young women (AGYW) are a particularly affected group because of their social and economic vulnerability. This diversity supplement application will build upon the parent grant to examine AGYW experiences accessing and utilizing maternal health services during pregnancy and postpartum in Zambia. The parent grant research team is collecting information on pregnancies among the study AGYW and health care service use but has not planned specific formal analysis related to potential barriers in seeking care for unintended or planned pregnancies, nor the outcomes related to these pregnancies. In this proposed supplement, Ms. Alinda Young (candidate) will explore barriers and facilitators to accessing health care and health-promoting resources that lead to optimal pregnancy outcomes and HIV outcomes. The proposed research will collect supplementary quantitative data and brief qualitative information through interviews with AGYW who have reported giving birth within the last 12 months while enrolled in the study. Furthermore, the team will conduct focus group discussions with parents and caregivers of AGYW enrolled in the parent study, peer navigators, providers, and advisory board members to understand their perspectives on AGYW seeking maternal health care. The supplemental study will use implementation science frameworks and approaches to ensure the proposed research yields actionable data to identify appropriate interventions to address barriers identified among this population. Barriers identified could also highlight a missing gap in current evidence-based interventions and would provide Ms. Young with the opportunity to submit a proposal focused on creating new or adapted interventions to address these barriers. Ms. Young will receive mentorship and training to improve her research skills and progress towards becoming an independent researcher. She will also work to submit an F31 grant after the completion of the planned research activities.