Summary Type I diabetes (T1D) is one of the most common chronic diseases in childhood. Sequelae of pediatric T1D include neurocognitive dysfunction in attention, psychomotor speed, mental efficiency, visual-motor skills, memory, and learning possibly due to damage to posterior white matter tracts and associated gray matter regions. Emerging evidence suggests that diabetic ketoacidosis at time of diagnosis, glucose control, diabetes device use, sleep, and caregiver distress may be important factors that influence neurocognitive development. However, there is minimal data in this area and existing studies are limited by small sample size, short follow-up time, and a lack of diversity in patient populations. A contemporary, adequately powered longitudinal study in a diverse cohort of prepubescent children is needed to understand the mechanisms associated with neurocognitive perturbations, critical periods for prevention and intervention, and strategies to mitigate the risk of neurocognitive complications in later life. Our research team is uniquely qualified to serve as the Biostatistics Research Center (BRC) for the Understanding Neurocognition in Youth with Type 1 Diabetes (UNYT1D) nation-wide consortium combining extensive experience in the coordination of multi-site clinical studies and research networks, biostatistics expertise in the analysis of complex observational data, and expertise in T1D, glucose variability, neurocognition, and neuroimaging. Our application leverages the existing infrastructure of the University of Minnesota’s Coordinating Centers for Biometric Research (CCBR), which has internationally recognized expertise in coordinating complex, large-scale, multi-site studies and networks and over 50 years of experience These substantial strengths enable the BRC to accomplish the following specific aims:1) Partner with NIDDK to provide scientific leadership in the design of a longitudinal cohort study to characterize the neurocognitive impact of new onset T1D in pre-pubertal children; 2) Provide overall coordination of the national multisite consortium in the planning and implementation of and adherence to the protocol; 3) Provide consortium-wide resources for data harmonization, pipelines, management and sharing; 4) Provide expertise in all aspects of study reporting, data analysis and dissemination. The BRC will play a crucial role in the success of the consortium. Our research team has a proven track-record of high-impact research in the clinical management of T1D, a history of developing novel approaches to neuroimaging data acquisition and analysis, and extensive experience coordinating the activities of and providing statistical and data management support for multi-site clinical studies and research networks. Leveraging this experience and capitalizing on the existing infrastructure of the CCBR, we are uniquely suited to serve as the BRC and support high-quality, robust, and reproducible research through the UNYT1D consort...