PROJECT SUMMARY Adolescents with type 1 diabetes struggle more than any other age group to meet recommended glycemic targets. Continuous glucose monitoring devices, which enable real-time determination and communication of blood glucose levels, identification of trends, alerts, and alarms, and remote communication and monitoring, have improved metabolic and lifestyle outcomes and have markedly transformed the clinical management of diabetes in youth. However, these technological improvements have not benefited all populations similarly: lower rates of uptake and continued use of these devices in Black and Latinx young people have exacerbated pre- existing racial disparities in diabetes care and outcomes. Beyond socioeconomic issues such as access, developmentally and culturally specific factors relating to burden, diabetes distress, and self-efficacy are modifiable targets for specific and innovative interventions. Structured peer mentoring programs have been successfully employed in other chronic illness models to improve attitudes and behaviors around disease management. Using a stakeholder engagement approach, we will develop, optimize, and evaluate a peer- support intervention, Glu-COACH, to improve the uptake and maintenance of CGM use in Black and Latinx adolescents with type 1 diabetes. The input from a stakeholder panel representing patients, parents, and clinicians will inform each phase of the study. In Phase 1, we will collaboratively develop Glu-COACH and finalize study protocols with our stakeholders. In Phase 2, we will conduct a randomized controlled pilot study (n=50) comparing Glu-COACH to an enhanced standard care control group, convening quarterly research progress meetings with our stakeholders for ongoing collaboration. We hypothesize that the support, validation, identification, vicarious experience, and role modeling provided by trained peer mentors of the same cultural identity will significantly improve our primary aim of CGM use in Glu-COACH participants compared to the control group. We will also examine the effects of the Glu-COACH intervention on glycemic outcomes, such as time in range, mean glucose, and A1c, and behavioral outcomes, such as diabetes-related self-efficacy and distress, as well as benefits and burdens related to CGM use. Finally, we will critically examine the feasibility, acceptability, and implementation of the Glu-COACH intervention. This intervention will be upscaled and evaluated in a subsequent multi-site randomized controlled trial if proven effective.