Research has consistently shown that 3- and 4-year-olds who attend a high-quality preschool are more successful in kindergarten and beyond--both academically and socially. But the majority of preschool programs in the United States are not judged as good, with many rated far below that. Many of our most vulnerable children attend the lowest quality programs, and children who are at risk for school failure are more strongly influenced by the quality of preschool. Noting that momentum is building across the country to develop more preschool programs, this policy brief provides a vision of what high-quality preschool programs look like, and offers recommendations for improving quality. The brief uses the latest research findings and best practices recommended by the National Association for the Education of Young Children (NAEYC) to describe the process and structural features of a high-quality preschool program in terms of what is critical for the child, family, teacher, curriculum, and classroom. Based on these indicators of quality, the brief's policy recommendations are as follows: (1) develop state standards for all preschool programs; (2) increase teacher salaries and benefits to levels similar to those of comparably qualified K-12 teachers; (3) develop valid measures of early educational quality that incorporate the recent research on early literacy, mathematical, scientific and social-emotional learning; (4) provide continuous training and quality improvement efforts to all preschool teachers and programs; and (5) work together at federal, state, and local levels of government to establish a coordinated system of high-quality education and care for all 3- and 4-year-olds. (Contains 20 endnotes and a list of 32 additional resources. (HTH)