This chapter summarizes the transition of medical care from pediatric to adult providers for adolescents and young adults with type 1 diabetes mellitus. The chapter includes a patient case, case discussion, and a complete didactic section that covers the definition and epidemiology of the disease and potential microvascular and macrovascular complications of uncontrolled diabetes and their recommended screening. Furthermore, the chapter highlights several common coexisting conditions in emerging adults with diabetes, including mood disorders, disordered eating, and other accompanying autoimmune diseases. Critical issues in caring for emerging adults with diabetes are also discussed, including substance use, sexual health and preconception planning, financial barriers to transition and health insurance, preparation for changing living situations, and entering the work force or college. The chapter also provides multiple resources for the pediatric and adult health care team as well as the patient and family to help prepare and empower the emerging adult with diabetes for the transition to adult medical care.