Foster care provides round-the-clock substitute care for nearly 700,000 U.S. children who are temporarily or permanently separated from their family of origin each year. Each state manages its own foster care system according to federal regulations. Despite numerous large-scale federal policy reforms over the past several decades, substantial concerns remain about the experiences and outcomes of children in the foster care system. The most recent effort to reform foster care, the Family First Prevention Services Act of 2018, attempts to both reduce the use of foster care and increase the quality of care. In this report, we review how policy has shaped the experiences and outcomes of children in foster care, where policy has succeeded, and where it falls short of achieving its goals. We then identify opportunities for federal and state policy to better support the safety, health, and well-being of children in foster care.