Medical interventions for life-threatening pediatric conditions often oblige ongoing and complex medical care for survivors. For some children with medical complexity, their caretaking needs outstrip their parents' resources and abilities. When this occurs, the medical foster care system can provide the necessary health care and supervision to permit these children to live outside of hospitals. However, foster children with medical complexity experience extremes of social and medical risk, confounding their prognosis and quality of life beyond that of similar children living with biologic parents. Medical foster parents report inadequate training and preparation, perpetuating these health risks. Further, critical decisions that weigh the benefits and burdens of medical interventions for these children must accommodate complicated relationships involving foster families, caseworkers, biologic families, legal consultants, and clinicians. These variables can delay and undermine coordinated and comprehensive care. To rectify these issues, medical homes and written care plans can promote collaboration between providers, families, and agencies. Pediatricians should receive specialized training to meet the unique needs of this population. National policy and research agendas could target medical and social interventions to reduce the need for medical foster care for children with medical complexity, and to improve its quality for those children who do.