The incidence of type 1 diabetes (T1D) is increasing globally with the most substantial increases occurring in the youngest age groups. A growing number of youths with T1D must therefore transition their healthcare from pediatric to adult T1D care settings as they approach young adulthood. This healthcare transition introduces many challenges because it coincides with a developmental period that is fraught with social, financial, residential, school/work and other changes/demands. Thus, it is not surprising that young adults (YA) with T1D are at risk for suboptimal glycemic levels, the development of diabetes-related complications, and psychosocial issues such as depression, anxiety, and disordered eating. Yet, few evidence-based interventions to assist YA with T1D with this complex healthcare transition exist. In this study, we are testing the feasibility, acceptability, and initial efficacy of a novel transdisciplinary model of care (Transdisciplinary Care for Transition; TCT) in which a diabetes nurse educator, psychologist, and transition navigator (case manager) co-deliver transitional care. TCT addresses the psychological and systems barriers to transition and aims to improve outcomes via better assessment of YA needs and resources, better cross-discipline and YA-provider communication, and better collaboration with YA to resolve problems that cross pediatric and adult healthcare settings. We will recruit 80 YA with T1D during their final visit in pediatric T1D specialty care to participate in a pilot randomized controlled trial during which we will randomize YA to a standard care control group (SCC) or to receive three TCT visits during the 6 months post discharge from pediatric T1D care. In SCC, participants will transition to adult T1D care as usual per their clinic's standard transition procedures. All study procedures can be completed remotely. This includes enrollment, study evaluations, and TCT visits for those randomized to TCT. Thus, we are recruiting individuals from across the United States. Aim 1: Examine the feasibility, acceptability, and fidelity of TCT in YA with T1D. Aim 2: Examine the preliminary efficacy of TCT versus SCC on YA HbA1c, transition readiness and success, and continuity of care and explore for an effect on diabetes distress and acute care utilization.