School attendance is an important predictor of student outcomes. Regular attendance ensures students have access to learning in the classroom and allows students to build relationships with their peers and adults in schools. But too often, students face barriers in and out of school that influence whether they attend school consistently. These high levels of chronic absence have exacerbated educational and societal inequities that existed long before COVID-19. Students from low-income backgrounds, students of color, students whose families speak languages other than English, and those with disabilities are more likely to be chronically absent from school -- and may lack the resources and opportunities to make up for lost time in the classroom. This report lists five things that advocates should know about how leaders can address chronic absence: (1) Chronic absence is often hidden; (2) Chronic absence is a reflection of the school and community environment; (3) Punitive responses are not effective; (4) Improving attendance requires prevention and early intervention; and (5) Reducing chronic absence requires authentic partnerships with students, families, and communities.