Many Americans assume children's publicly funded education begins with kindergarten. To the contrary, kindergarten is not mandated in all states. Moreover, most kindergarten programs implemented in the public education system are half-day; full-day kindergarten is far less frequent. Access to kindergarten is highly dependent on state, school district, and individual school initiatives and resources. Thus, kindergarten provision is an educational equity issue. Kindergarten is a pivotal transitional year in which children learn foundational skills and develop knowledge necessary for academic success in the early grades. Considering this crucial role, it is surprising how often kindergarten is overlooked when research and education policy agendas are formed. Neither states, nor the federal government, collect enough systematic data on kindergarten, especially at a school district or individual school level. Extant data sources differ in reported state kindergarten policies. Thus, an accurate picture of the availability, utilization, and content of kindergarten programs at a national or state level is not available. Current policy debates include mandating kindergarten, requiring attendance, and establishing a uniform entrance age. Further, consensus has not been reached as to what is appropriate in kindergarten for curriculum content, instructional methods, and screening and assessment practices. Distinct roles for prekindergarten and kindergarten should be defined and programs should be coordinated to promote better continuity in learning. Research indicates that delaying entrance to kindergarten results in only ephemeral effects and that full-day kindergarten has academic and practical benefits for children and families. Finally, state and federal recommendations range from revising data collection polices to aligning kindergarten policies and practices to prekindergarten and grades 1-12. [This issue of "Social Policy Report" also contains "Opening Pandora's Box: Discovering Kindergarten as a Neglected Child Policy Issue" (Ruby Takanishi).]