.How best to transition adolescents and young adults—particularly medically complex individuals or those with a chronic illness or disability—from a pediatric to an adult system of health care remains a largely unanswered question. Challenges to a smooth transition include being able to identify those most in need of transition planning, locating suitable adult medical homes, being adequately reimbursed for transition planning, and providers' lacking sufficient training about the transition process and the care of medically complex adolescent and young adult patients. To highlight the importance of developing and implementing successful transition models, the Archives of Pediatrics & Adolescent Medicine will publish a rolling theme issue this year focusing on this topic. We are interested in original articles, narrative and systematic reviews, and commentaries that will add to the scientific knowledge about this emerging area of health care. Original articles might include randomized trials or controlled studies comparing varying mechanisms for transferring these patients, practice-based systems interventions that help practices prepare for the transition or receipt of these youth, comparisons of the quality of care provided to patients with the same illness delivered in different settings and/or by different kinds of clinicians, educational interventions that enhance the transition skills of pediatric and/or adult providers, or assessment of patient satisfaction among different models or before and after transfer of care.