Chronic absence is a national crisis, dragging down achievement for students across the country. Attendance Works defines chronic absence as missing 10 percent or more of school days for any reason--excused or unexcused as well as suspensions. The purpose of this brief is examine the role of state policy and action in ensuring chronic absence is monitored and addressed. To provide a common understanding of the issue, it reviews key underlying concepts before offering policy recommendations. The brief includes the following sections: (1) Why paying attention to chronic absence matters for student achievement; (2) Why chronic absence is overlooked; (3) Why students miss school; (4) What reduces chronic absence; (5) What states can do; and (6) What states could ask the federal government to do. An Appendix offers profiles of how different states have begun to address chronic absence and improve attendance.