States across the country are urgently building and initiating systems to improve schools, including those identified as low-performing under the Every Student Succeeds Act (ESSA). With their state ESSA plans approved by the U.S. Department of Education in 2017-2018, state education agencies (SEAs) are moving forward to carry out the vision, requirements, and opportunities put forth in the legislation. ESSA introduces new responsibilities and opportunities for SEAs, local education agencies (LEAs), and schools, especially in regard to school improvement. At the time of this report, SEAs are working closely with stakeholders at the local and state levels to innovate and learn as they go to do what is best for students. This report gathers timely comprehensive information across SEAs on how state leaders are working to implement their vision for school improvement under ESSA. The goal is for SEA leaders to use the information, resources, and examples provided in this report to inform their school improvement efforts. This report is one resource in a broad portfolio of assistance and resources provided by the Council of Chief State School Officers (CCSSO) on ESSA and school improvement. It focuses narrowly on school improvement and does not address SEA work around accountability or identification of schools. This report is organized by 7 domains of SEA responsibility related to ESSA school improvement. Each report section describes SEA responsibilities and opportunities for improving schools, along with state examples and resources. Curated resources appear in an appendix, ordered by the same 7 domains of SEA responsibility. The appendix includes resources published by the CCSSO, materials that states are using, and other documents relevant to school improvement under ESSA. [Derek L. Riley, Julie Meredith, and Alisha N. Butler assisted in developing this report.]