The transfer of young people with type 1 diabetes (T1D) to adult care occurs during a critical period of life, while many young people with T1D have unsatisfactory glycemic control. The preparation to take over responsibility for their health and self-care as well as increasing their participation in care are important aspects for strengthening people’s own ability, an important component of person-centered care. STEPSTONES-DIAB aims to evaluate the effectiveness of different transitional care models in adolescents with T1D to empower them to become active partners in their care. The study is conducted at three hospitals in Stockholm, Sweden. In two hospitals 140 patients will be randomized to either a structured, person-centered transition program over a 2-year period or to usual care. The third hospital with a dedicated youth clinic will serve as a comparison group, 70 patients will be included at the youth clinic. This type of youth clinic is unique in Sweden and has not previously been evaluated. Outcome measures is empowerment, participation and responsibility in care, health status, glycemic control as well as the participants’ experiences of care during transfer.