Summative assessments measure students' mastery of grade-level academic standards and skills in specific content areas after learning. State summative assessment systems provide students and families, school and district leaders, and state policymakers with valuable data to help understand student progress and school quality. This Policy Guide provides comprehensive information about the federal policies governing state summative assessment systems, flexibilities available to state leaders in designing and administering summative assessments, and opportunities for innovation. It offers considerations for state leaders as they examine their own assessment systems and highlights state examples of various approaches to summative assessments.