Despite a large and growing body of evidence pointing to the short-term benefits of early learning programs across the United States, there is considerable variation in children’s PreK experiences with respect to classroom structure, the interactions in which children and families engage, and the quality of instruction delivered. This introduction to a special issue of Early Childhood Research Quarterly reports on a range of studies from across the United States that were designed to explore factors influencing high-quality learning experiences during PreK and across the transition into early elementary school. The introductory article sheds light on practices being used to improve early educational quality and enhance alignment in learning which can guide future research, practice, and policy.