Poor retention in HIV care programs is an obstacle in achieving the last two 90s in UNAIDS' 90-90-90 targets and end HIV by 2030. Peer support represents a potentially widely generalizable and cost effective strategy to enhance engagement in HIV care, but to date, a wide variety of peer-based interventions exist and the most effective specific use of peers is not well understood. An existing R01 co-led by UCSF and KEMRI that uses a peer-based navigation, known as personalized adaptive care (PAC), seeks to extend existing peer models through creating dynamic and longitudinal relationships between peers and patients that allowdelivery of information, knowledge, and support in a more personal and trusting manner. This proposal seeks tobuild on this existing study by taking a qualitative and deeper look at the experiences of both navigators their patients. This proposal, therefore, seeks to use a longitudinal qualitative design in which we will enroll and follow up 16 patients and 4 PAC navigators with interviews at three time points to: (1) assess how peer navigators understand and implement the PAC strategy, specifically how navigators understand, grapple with and internalize a patient centered, on-going, open-ended relationship with patients having retention challenges; (2) describe the nature of navigator-patient relationships created and their effect on treating patients retention challenges. In-depth interviews will be conducted by experienced qualitative interviewers and resultant transcripts coded and analyzed using NVivo program. Analysis will be done according to a modified grounded theory approach for theme and content to develop conceptual networks that illustrate relationships within and between participants . The conclusions will allow for structured contextual assessment of experiences with PAC as well as drivers and pathways to successful treatment of the retention lapses. Data from this study will be used to improve peer-based interventions to support the cascade of HIV care and treatment in Africa.