We propose to build on our experience with respondent-driven sampling (RDS) as the foundation of “seek and test”, by rigorously assessing three scalable strategies aimed at improving the “treat and retain” steps of the HIV care continuum among PWID in a LMIC setting. Aim 1 is to conduct a factorial randomized controlled trial to evaluate the individual and combined effects of a policy intervention (same-day ART), a structural intervention (community-based care) and an individual-level intervention (psychosocial/ navigation) to improve treatment outcomes among HIV-positive PWID. Aim 2 is to characterize the barriers and facilitators to implementation of the proposed interventions, and determine the intervention costs and potential cost-effectiveness.