The Handbook on Personalized Learning for States, Districts, and Schools is presented by the Center on Innovations in Learning (CIL), one of seven national content centers funded by the U.S. Department of Education (ED). In 2014, CIL published the Handbook on Innovations in Learning that responded to a call by ED to "leverage the innovation and ingenuity this nation is known for to create programs and projects that every school can implement to succeed" (2010, p. v). With the recent advent of the Every Student Succeeds Act (ESSA; the new federal education law replacing No Child Left Behind) new opportunities are available for flexibility for states, districts, and schools in support of student learning. The "every" in ESSA presupposes an approach to learning that allows individual student growth for every student and for new ways for educators to implement a personalized learning approach that includes students advancing at their own pace toward rigorous benchmarks on a pathway to college, career, and citizenship; implementation of online and blended learning formats; and for rethinking and redesigning assessments to allow a personalized approach to assessing student growth rather than summative assessments. The earlier volume focused on the harnessing of innovation to improve school success, and the authors presented chapters on defining innovation in the educational context and considered a number of best practices on emerging topics. Chapters in this new Handbook reflect the personalized learning goals of ESSA and reflect the view of personalized learning as a learning innovation.