Formerly excluded from measures of educational performance, students with disabilities (SWDs) are now explicitly recognised in federal and state accountability systems. At the national level, the 1997 amendments to the Individuals with Disabilities Education Act (IDEA) laid the foundation for accountability for SWDs by requiring states to include these students in state and district assessments and to report their participation and performance. This requirement was further reinforced by the Elementary and Secondary Education Act (ESEA), as reauthorised in 2001, which established SWDs as an explicit student subgroup for the purpose of determining whether schools make adequate yearly progress (AYP). The Institute of Education Sciences (IES) of the U.S. Department of Education (ED) has a congressional mandate to conduct a national assessment of how well the IDEA is achieving its purposes. As part of the national assessment of IDEA, this study is intended to provide policy-relevant information about the education of SWDs by examining their inclusion in school accountability systems and by describing the use of school practices that may relate to educational outcomes for these students. This book presents descriptive information on school-level accountability, AYP performance, and school improvement status of schools accountable for SWD subgroup performance under Title I of the ESEA, as well as schools not accountable for SWD subgroup performance. Moreover, the book presents descriptive findings focusing on school practices related to staffing, student support, instructional time, educational placements, teacher collaboration, and professional development in schools explicitly held accountable for the performance of the SWD subgroup and schools that are not accountable for the performance of the SWD subgroup.