The No Child Left Behind Act of 2001 (NCLBA) requires states to develop high-quality academic assessments aligned with state academic standards. The Department of Education (Education) has provided states with about $400 million for NCLBA assessment implementation every year since 2002. The US Government Accountability Office (GAO) examined: (1) changes in reported state expenditures on assessments, and how states have spent funds; (2) factors states have considered in making decisions about question (item) type and assessment content; (3) challenges states have faced in ensuring that their assessments are valid and reliable; and (4) the extent to which Education has supported state efforts to comply with assessment requirements. GAO surveyed state and District of Columbia assessment directors, analyzed Education and state documents, and interviewed assessment officials from Maryland, Rhode Island, South Dakota, and Texas and eight school districts in addition to assessment vendors and experts. Appended to this report are: (1) Objectives, Scope, and Methodology; (2) Student Population Assessed on ESEA Assessments in School Year 2007-08; (3) Validity Requirements for Education's Peer Review; (4) Reliability Requirements for Education's Peer Review; (5) Alignment Requirements for Education's Peer Review; (6) Item Types Used Most Frequently by States on General and Alternate Assessments; (7) Comments from the U.S. Department of Education; and (8) GAO Contact and Staff Acknowledgments. (Contains 1 table, 5 figures, and 30 footnotes.)