Nearly 750 000 children are currently in foster care in the United States. Recent trends in foster care include reliance on extended family members to care for children in kinship care placements, increased efforts to reduce the length of placement, acceleration of termination of parental rights proceedings, and emphasis on adoption. It is not clear what impact welfare reform may have on the number of children who may require foster care placement. Although most children enter foster care with medical, mental health, or developmental problems, many do not receive adequate or appropriate care while in placement. Psychological and emotional problems, in particular, may worsen rather than improve. Multiple barriers to adequate health care for this population exist. Health care practitioners can help to improve the health and well-being of children in foster care by performing timely and thorough admission evaluations, providing continuity of care, and playing an active advocacy role. Potential areas for health services research include study of the impact of different models of health care delivery, the role of a medical home in providing continuity of care, the perception of the foster care experience by the child, children's adjustment to foster care, and foster parent education on health outcomes. Pediatrics 2000;106:909±918; foster care, child welfare, children with special health care needs.