Black and Hispanic adults experience higher rates of diabetes-related morbidity and mortality than non-Hispanic whites. One primary reason for this disparity is their poor adherence to diabetes medicines. Not only do Black and Hispanic adults suffer more from complications related to uncontrolled diabetes than non-Hispanic whites, but their medication adherence rates are lower as well. Also, these diabetes disparities are strongly driven by social determinants of health (SDOH) barriers such as food insecurity, and health misperceptions - negative beliefs about diabetes/medicines, that negatively impact Blacks and Hispanics ability to manage diabetes including taking medicines. There is an immense need for effective diabetes self-management interventions that improve health outcomes for Black and Hispanic adults and reduce disparities. Our interdisciplinary team of experts in diabetes management interventions, medication adherence, health disparities, multiphase optimization strategy trials, mixed methods, and cost-effectiveness analysis will partner with an established pharmacy chain, and community partners to conduct a randomized factorial mixed methods trial to optimize diabetes management in Black and Hispanic adults with uncontrolled diabetes. This partnership will lead to the identification of an effective and cost-effective diabetes management intervention that reduces medication nonadherence and improves glycemic control (HbA1c) for Black and Hispanic adults by testing theory-driven intervention components/combination. This 6-month intervention will identify the intervention components/combination of components, i.e., (1) medication therapy management optimizing medication therapy, (2) community health workers addressing SDOH barriers to diabetes self-management and addressing diabetes and medicine misperceptions, added to usual care, that are effective in improving diabetes outcomes (effectiveness optimization) and are cost-effective (cost-effectiveness optimization). The expanded Chronic Care Model and Leventhal’s Extended Common Sense Model will be used to explain the contextual factors that put Black and Hispanic adults at a greater risk for diabetes disparities, and psychosocial and behavioral mechanisms to be tested. A randomized factorial mixed methods trial will evaluate the main effect of each intervention component and the interactions between intervention components to determine the optimal combination of components, that will have a long-term effect on (1) HbA1c, (2) medication adherence (assessed using self- report and pharmacy refills), and (3) psychosocial/sociocultural mediators of these outcomes. Finally, using qualitative interviews, we will explore the acceptability of each intervention component/combination as well as the effective/cost-effective components through understanding participant experiences. This project addresses an unmet critical need to optimize effective and cost-effective diabetes self-management interv...