Children from certain racial and ethnic minority backgrounds, in poverty, and/or with a disability, often face distinct challenges in attending school, leading them to miss more school relative to their non-minority, more socio-economically advantaged and non-disabled peers. This brief describes these disparities in absenteeism in the US, discusses the challenge of explaining these disparities, and considers the implications that disparities have for addressing absenteeism. Finally, it closes with advice on how schools can make headway in reducing disparities in absenteeism. As this brief argues, while schools can readily document absenteeism gaps, diagnosing the root causes of these gaps remains much more elusive. Further, schools seeking to reduce disparities in absenteeism will not only need to intentionally establish explicit targets to reduce such gaps, but they will need to develop individualized strategies to remove barriers to attendance thereby getting children--especially those facing disproportionate challenges--back into the classroom.