Publicly funded prekindergarten programs have achieved small‐to‐large impacts on children's cognitive outcomes. The current study examined the impact of a prekindergarten program that implemented a coaching system and consistent literacy, language, and mathematics curricula on these and other nontargeted, essential components of school readiness, such as executive functioning. Participants included 2,018 four and five‐year‐old children. Findings indicated that the program had moderate‐to‐large impacts on children's language, literacy, numeracy and mathematics skills, and small impacts on children's executive functioning and a measure of emotion recognition. Some impacts were considerably larger for some subgroups. For urban public school districts, results inform important programmatic decisions. For policy makers, results confirm that prekindergarten programs can improve educationally vital outcomes for children in meaningful, important ways.