With the passage of the Every Student Succeeds Act (ESSA), states gain considerably more authority and autonomy over the design of school accountability systems. This shift in responsibility creates the opportunity for states to reimagine new accountability models that align to goals of college and career readiness for all students and to move from a culture of compliance to one of continuous improvement. This report provides a resource to inform design and implementation decisions as state policymakers embark on the task of creating their next generation accountability systems. The authors discuss the limitations of using a single composite accountability index, advance principles and a conceptual framework to drive next generation accountability, describe potential indicators of what they call an "Educational Quality and Improvement Profile," and offer recommendations to guide the design and implementation of these new accountability systems. [For the research brief, see ED606770.]