Congress promised 40% of special education's cost. It pays a quarter of that promise.

Every child with a disability in this country has a federal right to a free, appropriate public education.▸ That right was never free to provide, and Congress knew it: when it enacted the law in 1975, it promised to cover 40% of the extra cost of educating those children — the "excess cost" above what a general-education student costs. Fifty years and every intervening budget later, Washington has never once kept that promise. FY2025 is not an exception; it is the rule.

The formula is simple: the Education for All Handicapped Children Act of 1975 set the federal government's share of special education's added cost at 40% of the national average per-pupil expenditure (APPE), multiplied by the number of children served.▸ That 40% figure became known as IDEA's "full funding" level, and it has never been reached. According to the Congressional Research Service's most recent primer on IDEA funding (updated February 13, 2026), the FY2025 appropriation for Part B — the program's grants-to-states core — amounted to approximately 10.2% of the national APPE, "just over 25% of the full funding level." The single closest the program has ever come was FY2009, when one-time American Recovery and Reinvestment Act stimulus dollars, layered on top of regular appropriations, briefly pushed funding to almost 35% of APPE — a stimulus artifact, not a policy choice Congress repeated.

In dollars, Part B was appropriated $14.214 billion for its Section 611 grants-to-states program in FY2025, plus $420 million for Section 619 preschool grants — $14.634 billion total, per the CRS report, unchanged from FY2024.▸ That money reached roughly 7.9 million children ages 3 through 21 who received special education and related services under Part B in the 2023-2024 school year. Everything the 40% promise doesn't cover — nearly three-quarters of the added cost of serving those children — falls to state and local budgets, which is precisely the "undue burden" Congress said in 1975 it did not want states to bear alone.

A funding gap that size does not stay abstract.▸ It shows up first as a staffing problem, because someone still has to be hired to write the individualized education programs, run the pull-out sessions, and manage the caseloads the law requires — on budgets that were never built to the scale the law promised. The U.S. Department of Education's own annual shortage-area designations name special education as the most commonly reported shortage subject in the country: 45 states listed it for the 2024-25 school year, more than science (41 states) or math (40 states), according to the Learning Policy Institute's analysis of that federal data.

The NCES School Pulse Panel found special education the single hardest subject to staff at both the elementary and middle-school levels — 74% of schools at each level reported difficulty filling a special-ed vacancy with a fully certified teacher, ahead of every other subject tracked, including ESL/bilingual education and foreign languages.▸ High schools reported 66% difficulty, second only to ESL/bilingual education. These are not remote or rural outliers; they are national averages, collected the same fall the federal government funded barely a quarter of its own special-education promise.

Funding figures cover the Part B grants-to-states program (Sections 611 and 619); Part C (infants and toddlers) and Part D (national activities) are separately and more modestly funded and are not included in the 40% full-funding calculation. Hiring-difficulty figures are school-reported perceptions from a single fall 2024 survey wave, not a formal vacancy count.