This brief examines absences in September and students' attendance over the rest of the year. Attendance should be addressed before it becomes problematic. Chronic absenteeism, missing more than 20 days of a school year, is an early indicator of disengagement. High absence rates have negative consequences not only for individual students, but also for classroom instruction and school climate. These results suggest that schools need to pay attention to student attendance from the earliest days in September, and intervene to get students back on track quickly.