Following a high-quality early care and pre-K experience, the kindergarten-through-third-grade years set the foundation upon which future learning builds; and strengthening this continuum creates opportunities for later success. Key components of a quality experience in K-3 include school readiness and transitions, kindergarten requirements, educator quality, prevention, intervention and assessments, and social and emotional learning and mental health. Education Commission of the States researched the policies and regulations that guide these key components in all 50 states to provide this resource and many others. The data in this document show that at least 20 states have literacy requirements for pre-service and in-service educators. An additional 20 states have literacy requirements for teacher candidates, with three states having solely requirements for in-service professional development related to literacy. At least five states have grant funding that is used to provide in-service educators with professional development, subject to availability. Seven states plus Washington, D.C., do not specify requirements in statute or regulation; however, many states do outline professional development plans and resources online.