The PARC study, conducted in Tanzania, was set up to better understand barriers and enablers to retention and engagement in HIV care among adult patients who are enrolled in HIV care and are not yet eligible for ART. The study seeks to describe barriers and enablers to retention and engagement in HIV care and to estimate the incidence of short-term outcomes, including the rate and proportion of disengagement from HIV care, death, and transfer out. In addition, the PARC study also conducted qualitative interviews and focus groups on perceived barriers to engagement as well as exhaustive patient interviews to obtain baseline information on potential determinants of disengagement from care among ART-ineligible patients. The findings of the study will help design interventions to maximize retention and engagement in HIV care. Partners in this study include Columbia University-ICAP and the National Institute for Medical Research of Tanzania.