Student absenteeism has recently entered the national spotlight with its emphasis in the Every Student Succeeds Act, and here in California with its inclusion in the School Dashboard. Yet many questions remain about who chronically absent students are and how they are concentrated within schools. In chapter 1 (of the edited book, Absent from School), the author uses data from the CORE districts—which serve nearly one million students in over 1,000 schools in California–to better understand differences across students and schools, comparing these measures to a broader set of school performance indicators. First, the author describes attendance at the student level and how it varies by student characteristics. Then, she shows how schools perform on this metric, by school type, by subgroup, and across time. Finally, she describes how schools’ performance on chronic absence metrics corresponds to other accountability metrics and the related implications for reporting school-level measures of chronic absenteeism.