This bill, known as the "IDEA Full Funding Act," proposes to amend the Individuals with Disabilities Education Act (IDEA) to ensure full federal funding for Part B, fulfilling the original intent of the law. It establishes a clear, escalating schedule for federal appropriations over a decade, aiming to significantly increase the federal contribution to the education of children with disabilities. The legislation mandates specific appropriation amounts and percentages for each fiscal year from 2026 through 2035 and subsequent years. For each year, the funding level will be the greater of a fixed dollar amount or a specified percentage of a calculated total, which is derived from the number of children with disabilities aged 3 through 21 receiving services multiplied by the national average per-pupil expenditure. By fiscal year 2035, the bill targets a federal contribution of 40% of this calculated amount. These appropriations are designed to become available for obligation on July 1 of the respective fiscal year and remain available through September 30 of the succeeding fiscal year, ensuring continuity in funding. Additionally, the bill stipulates that all appropriated amounts must be expended consistent with "cut-as-you-go" requirements , emphasizing fiscal responsibility in the implementation of this increased funding.