PROJECT SUMMARY ABSTRACT In this application, we propose to scale up an Evidence-Based Intervention- TXTXT- by creating a regional hub in the Midwest to coordinate broad dissemination, and to greatly increase reach and impact. We will evaluate the implementation of the EBI scale up via a hybrid type II design to inform the broad dissemination of a region-based implementation model and will elaborate a sustainability plan for TXTXT to inform wide scale dissemination and rapid scale up to additional US regions. Specific Aims: 1. Determine the real-world efficacy of a regional scale up of an EBI- TXTXT- on our primary and secondary outcomes: adherence, viral load suppression, and retention in HIV care, respectively, among poorly adherent racial/ethnic minority YLH, ages 16-35 at 3-and 6-month follow-up. 2. Apply the Consolidated Framework for Implementation Research (CFIR) to describe the implementation process and identify barriers and facilitators needed to be addressed; and measure implementation outcomes of the TXTXT intervention using the RE-AIM framework (Reach, Efficacy, Adoption, Implementation, Maintenance). Dr. Johnson is an ideal candidate for an HIV-focused Implementation Science mentorship award. She is a trained Infectious Disease Epidemiologist with initial certification in Implementation Science approaches and methods (not yet applied). As an early career HIV prevention scientist, she has a breath of experience that stems from community-engaged research which includes basic science, including surveillance and epidemiology as well as intervention development and capacity development initiatives. The next logical step is to gain skills in systems-level implementation science and sustainability planning to inform broad dissemination of evidence-based interventions. This study combines behavioral and social science, implementation science, and information dissemination towards the ultimate goal of public health impact. Medication adherence is a key driver of viral suppression and this regional TXTXT initiative, with a longer-term objective of national dissemination and focused on patients at most risk of virologic failure will directly address local, regional and national goals to End the Epidemic by 2030.