Transfer of youth with chronic health conditions to adult care is often suboptimal due to factors such as emotional and cognitive developmental challenges, lack of individual and family-centered social supports, communication and coordination challenges between health care sectors, and a lack of appropriately trained adult health care providers. Decline in health after transfer of care to adult health care providers is well described, possibly due to lapses in adherence, follow-up, and insurance coverage; however, most studies reporting this phenomenon have focused on single populations such as those with sickle cell disease, diabetes mellitus, or organ transplantation, and relatively little is known about those with chronic mental health and neurodevelopmental conditions.