This study traced the determinants of selected provisions of P.L. 108-446, the Individuals with Disabilities Education Improvement Act of 2004 (IDEA 2004), in the communications of federal commissions and stakeholder groups that tried to influence the formulation of the legislation in the U.S. House of Representatives. It used a qualitative form of content analysis to compare the text of IDEA 2004 with these communications and found that the Thomas B. Fordham Foundation, a politically-conservative think tank that had been given unprecedented access to the process by the Bush administration, played a significant indirect role in shaping the reauthorization agenda in Congress through affiliations among the editors and chapter authors of its book, Rethinking Special Education for a New Century, and leaders and members of the President's Commission on Excellence in Special Education and the House Education and Workforce Committee. General education professional associations and school governance organizations proved to be the most influential stakeholders, however, particularly when compared to families of students with disabilities, disability advocacy groups, and special education professional associations, whose participation and input was limited by Congressional leaders who feared a repeat of the controversial 1997 reauthorization. Recommendations are aimed at preventing such marginalization of disability interests in future reauthorizations and re-establishing the nonpartisan, transparent and accessible character of past reauthorizations.