Black men are more likely to be diagnosed with Type 2 diabetes (T2D) compared to non-Hispanic White men.Black men with T2D also experience suboptimalglycemic controlcompared to non-Hispanic White men, resulting in a higher risk for complicationsassociated with T2D. A growing body of literature demonstrates the critical role of gender in the management of health behaviors forchronic conditions such as T2D; male gender norms can negatively impact implementing healthy behaviors. Broader literaturedemonstrates that gender-based beliefs, like maintaining a strong image to the outside world, impedeengaging in healthy behaviors. These studies suggest that tailoring T2Dself-management interventions to address the needs of Black men may be critical tohelping them to achieve optimal health outcomes. Peer leaders are trained lay individuals who provide ongoing T2Dself-management support to people with T2D, particularly in minority communities. Despitestudies showing that T2Dmanagement interventions using peer leaders have been successful, the majority of peer leaders andparticipants in those studies are women. The limitedstudiestodatesuggestthatBlackmenwithT2Dpreferpeer-led,male-to-maleT2Dprograms;however, this research consists primarily of nonrandomized, small sample feasibility studies focused on disease prevention and screening. The proposed study will develop and preliminarily validate the effectiveness of an adapted Peer Leader Diabetes Self-Management Support (PLDSMS) intervention designed to improve diabetes-related self-management behaviors in Black men with T2D. The proposed study includes a developmental phase (development of the intervention with expert feedback, followed by feasibility testing withBlack men) and a pilot validation phase.This study aims to 1) tailor existing PLDSMS interventionsbyconsulting Blackmale peerswith T2D in 2 focus groups and modifying the peer leader training content to focus on material appropriate for menusing Self-Determination theory, Autonomy Support and the Empowerment Approachas guiding frameworks, and 2) to conduct a pilot validation phase [pilot randomized clinical trial (RCT)] to evaluate participant recruitment and retention rates, treatment and intervention satisfaction, and estimate intervention effect sizes on our primary outcomes (self-management behaviors and glycemic control [HbA1c]) as well as on secondary outcomesin a 36-week RCT with a repeated measures design.Participants (n=60) will be randomized into the adapted PLDSMS intervention group or Enhanced Usual Care group. If successful, this study will lead to the development of an R01 intervention that will address the unique needs of Blackmen with T2D, helping them to achieve optimal T2Dself-management and healthoutcomes.