The Every Student Succeeds Act (ESSA), signed into law in December 2015, is the latest reauthorization of one of the most influential pieces of federal education legislation, the Elementary and Secondary Education Act (ESEA). The law had not been reauthorized since 2001 when the No Child Left Behind Act (NCLB) was signed, and ESSA is the result of significant bipartisan effort to move beyond temporary waivers from NCLB's provisions. The new law maintains many of the same basic components as past iterations, such as state plans and report cards, but the bipartisan bill also responds to many of the common complaints about NCLB by offering states greater flexibility and control over education policy. Many questions remain before states can fully take advantage of ESSA. This report addresses the areas of the law where Education Commission of the States has heard the most questions and concerns from education leaders and policymakers. The following topics are included: (1) Assessment Flexibility; (2) Assessment Participation and Opt-Outs; (3) Innovation Assessment Pilot; (4) Indicators of School Quality or Student Success; (5) English Learners and Accountability; (6) Supporting Low-Performing Schools; (7) Teachers and School Leaders; (8) Title I's Supplement-Not-Supplant Provision; (9) Title IV--21st Century Schools; and (10) State Plans.