The entry into kindergarten is a key transition children experience and has lasting consequences for their academic development. In light of this, many schools have implemented transition practices designed to foster positive development for children during this time. This study uses qualitative interview data to examine the policies, practices, and barriers that shape how school districts support children during the kindergarten transition. Data from interviews with teachers and administrators in eleven school districts reveal a diversity in the number of kindergarten transition practices implemented and a number of structural barriers related to communication and collaboration that prevent more intensive transition efforts. These barriers included a lack of communication about children's experiences prior to kindergarten and practical challenges related to bringing early childhood educators and elementary personnel together. They also highlighted external policy factors, such as quality rating systems, that shaped transition practices. These findings point to a number of future directions for both research and policy related to the kindergarten transition. [This paper was published in "Early Childhood Research Quarterly" v52 p5-14 2020.]