A recent report commissioned by the Office of the District of Columbia Auditor examined the accuracy of enrollment projections by the District of Columbia Public Schools (DCPS) and by charter local educational agencies (LEAs). While the report found that enrollment projections were fairly consistent with LEA level enrollment, based on a sum of October-audited school enrollments, the report found inaccuracies in school-level enrollment projections. More specifically, less than 40 percent of school-level enrollment projections were within two percentage points above or below the projection. Importantly, the report found that errors in school-level enrollment projections were greater in certain Wards, in transition grades, and in schools with more student mobility or "churn." The prior report only minimally addressed how factors such as student mobility and school demand--both of which affect a school's enrollment and therefore its funding--related to the accuracy of enrollment projections. In addition, the prior report did not address the accuracy of enrollment projections for specific student subgroups that receive additional funding in the District's Uniform Per Student Funding Formula (UPSFF). This study provides a more robust investigation into the relationship between enrollment projection accuracy and factors that likely influence the accuracy of projections. Additionally, this study seeks to better understand the accuracy of enrollment projections for specific student subgroups that receive additional funding: special education, English learner, and students considered "at-risk." In the District, the "at-risk" classification includes students in families qualifying for the Supplemental Nutrition Assistance Program (SNAP) or Temporary Assistance for Needy Families (TANF) program and students who are homeless, in foster care, or over-age for their grade in high school. Key findings and recommendations from this study are summarized in the following sections. [This report was prepared for the Office of the District of Columbia Auditor (ODCA) by the Center for Research and Reform in Education.]