The No Child Left Behind Act (NCLB), the most current revision of the Elementary and Secondary Education Act of 1965 notwithstanding, the more than 100 page long Individuals with Disabilities Education Act (IDEA) is the most comprehensive, expensive, and litigated federal statute impacting on public education in the United States. Enacted initially in 1975 as the Education for All Handicapped Children's Act, the IDEA is designed to provide a free appropriate public education in the least restrictive environment for all students with disabilities between the ages of three and 21. Previously revised most recently in 1997, the United States Congress has, as with many other statutes, periodically re-examined the provisions of the IDEA in an attempt to ensure that the Act meets the educational needs of students with disabilities. Not surprisingly, Congressional wrangling over the IDEA's provisions meant that the 2004 modifications took longer than expected to complete. After two years of off and on, and occasionally rancorous, debate, President Bush signed changes in the IDEA in the Individuals with Disabilities Education Improvement Act of 2004 into law on 3 December 2004. The new version of the IDEA became effective on 1 July 2005. In re-authorizing the IDEA, Congress enacted a variety of changes ranging from minor rewording and renumbering sections to major substantive revisions. In order to keep individuals in England who are interested in special education up to date on the key changes in the Act, this article identifies the major changes in the 2004 IDEA by generally reviewing them in the order in which they appear in the statute as it was authorized by Congress rather than attempting to list them in order of significance. (Contains 25 notes.)