We analyze policies that support and affect the provision and costs of child care in the United States. These policies are motivated by at least three objectives: (1) improving the cognitive and social development of young children, (2) facilitating maternal employment, and (3) alleviating poverty. We summarize this policy landscape and the evidence on the effects they have on the development of children and parents. We provide a summary of the use and costs of nonparental child care services; and we summarize existing policies and programs that subsidize child care costs, provide child care to certain groups, and regulate various aspects of the services provided in the United States. We then review the evidence on the effects that child care policies have on these objectives. We go on to discuss the existing evidence of their effects on various outcomes. Finally, we outline three reform proposals that will both facilitate work by low-income mothers and improve the quality of child care that their children receive. (author abstract)