Under the Every Student Succeeds Act (ESSA), every state must develop a plan to provide a quality education to all students, hold schools accountable for how all students achieve, and identify and help schools that are struggling. It matters greatly how California designs its accountability system and supports school improvement. Getting this right means ensuring the most marginalized students in our education system get the opportunities they need to succeed; conversely, missing the mark could allow stubborn opportunity and achievement gaps to persist. In July 2018, the U.S. Department of Education approved California's ESSA plan. Now begins the work of implementing the plan. In this brief we lay out what is in the state's final ESSA plan, what California is doing beyond the plan, and what else California's leaders must do to advance educational equity and excellence. [For the first two briefs in this series, see "The 5 Big Things We Are Looking for in California's ESSA Plan" (ED598142) and "The 5 Things We Were Looking for in California's ESSA Plan - How Did the State Do?" (ED587364).]