Preschool programs in the United States have expanded dramatically in recent decades. There has been significant scholarly attention to the implications of this for inequalities in children’s educational outcomes, but less attention to the implications for the work-family lives of parents. Drawing on data from 2001 to 2017 American Community Surveys, this paper examines how children’s preschool enrollment is associated with maternal employment, with particular attention to differences by mothers’ race, ethnicity, and nativity. Findings document unequal access to preschool programs across groups but also different patterns of association between children’s preschool enrollment and maternal employment. Immigrant mothers are doubly disadvantaged compared to their U.S.-born counterparts: Children are less likely to attend preschool, and when they do attend, this does little to facilitate maternal employment. The paper’s conclusion addresses limitations of existing preschool programs for work-family reconciliation, but also emphasizes that limitations are more severe for some families than others.