PROJECT SUMMARY Approximately 40% of Latino MSM with HIV do not achieve viral suppression—an estimate that has likely worsened due to COVID-19 Pandemic stressors such as unemployment, loss of health insurance, homelessness, and exacerbated mental health and substance use disorders caused by the COVID-19 pandemic. Antiretroviral therapy (ART) adherence is associated with decreased viral load, increased CD4 counts, fewer hospital days, slower disease progression, and longer survival. Adherence also helps prevent drug resistance and reduces HIV transmission risk. The primary objective of this study is to evaluate the efficacy of stepped care strategies to improve ART adherence among adult Latino MSM with HIV using a sequential, multiple assignment, randomized trial (SMART). The trial will compare a stepped care strategy of delivering TXTXT first and stepping up to remote patient navigation for non-responders vs. a stepped care strategy of delivering TXTXT + e-Navigation first and stepping up to EMA-supported e-Navigation for non- responders. Both, TXTXT (“Treatment Text”) and the foundations of the e-Navigation interventions are CDC evidence-based interventions (EBI). We propose to use a SMART design which explicitly allows building, testing, and optimizing stepped care strategies without compromising rigor or randomization. We propose three specific aims: Aim 1. Compare the immediate (6-month) and sustained (9- and 12-month) efficacy of two static (non-stepped) treatment regimens (TXTXT alone vs. TXTXT + e-Navigation) on ART adherence and viral suppression among Latino MSM with HIV. Aim 2. Compare the immediate (6-month) and sustained (9- and 12-month) efficacy of two stepped care strategies (TXTXT with added e-Navigation for non-responders vs. TXTXT + e-Navigation with added EMA support for non-responders) on ART adherence and viral suppression among Latino MSM with HIV. Aim 3. Identify baseline and time-varying moderators on the association between stepped care strategy and ART adherence and viral suppression among Latino MSM with HIV. The proposed study is innovative by culturally adapting and combining two EBIs, using a stepped care approach, remote patient navigators, adaptive EMA components, and a SMART design. The proposed study is significant because it provides data on the efficacy of two scalable EBIs in one efficient design and provides data on enhanced treatment options for non-responders. The study is also significant because it targets an NIH health disparity population (Latino MSM) and addresses multiple domains and levels of influence on health and health disparities. It also targets people living in an Ending the HIV Epidemic geographic focus area with the highest HIV diagnosis rate in the nation (South Florida), thereby supporting the objectives of reducing HIV disparities in populations at high risk and living in the Southern US.