Growing investments in preschool at the federal and state levels--particularly in evidence-based approaches to language acquisition and reading--are predicated in part on the hope that high-quality preschools might help close the gap between the school achievement of low-income children and their more affluent peers. Indeed, the problem is substantial: as early as preschool, poor children exhibit substantially lower scores on tests of early literacy and math abilities. Left unaddressed, gaps in school achievement in preschool and kindergarten don’t close and may widen over the ensuing elementary years. Equally concerning, the gains achieved in preschool programs like Head Start appear to decline as children age. How do we make the most of the promise of preschool, particularly as preschool programs scale up and become universal? How do we avoid the "fade out" of early positive effects as children transition to elementary school? Recent investments in testing new approaches to enhancing children's social and emotional development and their early math skills suggest a new direction to address these challenges.