 Transition is the planned movement of teens with chronic conditions from child-centered to adult-oriented healthcare. National bodies have published detailed guidelines about the importance of helping teens move to adult healthcare. However, there is no research regarding how to best organize and deliver Congenital Heart Disease CHD transition programs. Data is urgently needed. Therefore, the aim of this program is to develop research evidence that will better prepare health care providers to improve how they can help adolescents with transition. 