This paper presents the evaluation results of a self-management support (SMS) initiative in Tanzania and Uganda, which used quality improvement to provide self-management counseling, nutritional support, and strengthened linkages to community-based services for highest-risk patients (those with malnutrition, missed appointments, poor adherence, high viral load, or low CD4 count). The evaluation assessed improvements in patient engagement, ART adherence, and retention. Difference-in-difference models used clinical data (n = 541 in Tanzania, 571 in Uganda) to compare SMS enrollees to people who would have met SMS eligibility criteria had they been at intervention sites. Interviews with health care providers explored experiences with the SMS program and were analyzed using codes derived deductively from the data. By end-line, SMS participants in Tanzania had significantly improved visit attendance (odds ratio 3.53, 95% confidence interval 2.15, 5.77); a non- significant improvement was seen in Uganda (odds ratio 1.62, 95% confidence interval 0.37, 7.02), which may reflect a dose-response relationship due to shorter program exposure there. Self-management can improve vulnerable patients' outcomes-but maximum gains may require long implementation periods and accompanying system-level interventions. SMS interventions require long-term investment and should be contextualized in the systems and environments in which they operate.