Abstract Type 1 diabetes (T1D), one of the most prevalent incurable diseases of childhood, is associated with serious risk of morbidity and mortality due to the development of micro- and macrovascular complications. Complications can be prevented by treatment that achieves physiological or near physiological levels of glucose. Despite innovations in management over the past three decades, pediatric patients of African ancestry (AA) have persistently higher HbA1c than patients of white, European ancestry (EA). Higher HbA1c in AA patients is associated with both higher acute and chronic morbidity and mortality compared to EA patients. Thus, racial disparity in glycemic outcome and the development of complications is a major unresolved failure of current clinical pediatric diabetes treatment. Multiple factors contribute to high-risk levels of mean blood glucose (MBG) in pediatric AA patients compared to EA. AA patients have less access to insulin pumps, perform glucose testing less often, have less contact with diabetes management staff, and may have difficulty relating to management staff due to cultural and socioeconomic differences. Greater occurrence of hypoglycemia is another obstacle to achieving optimal glucose control. These considerations have led us to hypothesize that an intervention targeting this group of major management obstacles will sustainably reduce MBG to levels comparable to EA patients without increased hypoglycemia. In order to test this hypothesis, we will first (Aim 1) conduct focus groups with high- risk AA patients and their families to pre-test our intervention approach and receive feedback from them about how best to implement the program, allowing us to more specifically tailor the intervention to address their perceived barriers. This information will help guide the design of a new tailored intervention (Aim 2) for these patients. In Aim 2, we will demonstrate the feasibility and preliminary efficacy of safely reducing high-risk, complication-producing levels of MBG among AA patients with T1D in a randomized pilot study using innovative hybrid closed-loop pump technology combined with a customized culturally sensitive program of enhanced patient support. This approach will intervene simultaneously with multiple obstacles previously known and currently identified by participants that confront high-risk patients and interfere with optimal management. We have the benefit of an experienced and interdisciplinary investigative team with a track record of research productivity in this area. We have a large, well-characterized, diabetes clinic population. Our patients and families have enthusiastically participated in many clinical research projects in the past. We expect that the experience and insights gained from this project will inform the design and implementation of a subsequent larger effectiveness study to improve outcomes for high-risk pediatric patients with T1D. Frequently Used Abbreviations: AA=African ancestry, E...