Abstract For people living with HIV (PLWH), achieving and maintaining viral suppression has critical benefits for their health and for reducing the risk of transmitting HIV to others. Viral suppression is thus a critical cornerstone of the US program to end HIV. However, over a third of people in the US living with HIV do not have a suppressed viral load. Some groups, including younger people and Black people, have lower levels of viral suppression. Although transfeminine people (TFP) have shown rates of viral suppression comparable to other groups, there is ample evidence that they experience a multitude of barriers to sustaining viral suppression, including multiple forms of stigma and structural barriers to accessing culturally appropriate care. In addition, there are wide racial disparities in HIV care among transgender communities, with Black TFP experiencing some of the lowest levels of viral suppression. A deep understanding if required of the circumstances that surround gaining, sustaining or losing viral suppression. Most research to date has focused on individual factors associated with viral suppression status. This approach is limited in that it restricts the consideration of the causes of lack of viral suppression to individual characteristics or behaviors, and misses the broader contexts – stigma, discrimination, lack of health coverage, distance to healthcare providers, and structural racism – that shape the risk of PLWH for losing viral suppression. Further, understanding these multilevel predicators of loss of viral suppression is required to develop interventions that are responsive to the circumstances that shape risks for remaining or becoming unsuppressed. Thus, we propose to enroll and follow a cohort of PLWH – both MSM and TFP – to observe the patterns of gaining, sustaining or losing viral suppression, and to develop information that can be used to inform the development of new interventions to support ongoing engagement in HIV care and viral suppression. Drawing on over a decade of experience in recruiting and retaining sexual and gender minority people in limited- interaction research studies, we will develop nuanced data about the unique factors that shape viral suppression or lack thereof in different critical groups, including Black MSM and TFP, and younger MSM, that are inequitably impacted by lack of viral suppression.