The Individuals with Disabilities Education Act is among the most consequential pieces of federal education legislation ever enacted. Before its passage in 1975 — originally as the Education for All Handicapped Children Act — public schools routinely excluded children with disabilities from educational programs entirely. IDEA established that every child with a disability has the right to a free appropriate public education in the least restrictive environment, mandating services that had never before been systematically provided.
The federal government did not assume this mandate without acknowledging its cost. Congress built into the original law a commitment to share the financial burden — specifically, to cover up to 40 percent of the average per-pupil expenditure multiplied by the number of students served. That commitment has remained on paper for five decades. It has never been fulfilled.
What IDEA Promised
The 1975 legislation created a graduated federal spending schedule. By 1982, the law stated that “the maximum amount” of each state’s Part B grant would be equivalent to 40 percent of overall average per-pupil expenditure in the United States multiplied by the number of identified children in the state. As Education Week’s retrospective on 50 years of IDEA explains, appropriations are handled separately by Congress, and decades later, Congress has never come close to meeting the 40 percent threshold.
The law was reauthorized in 2004 as the Individuals with Disabilities Education Improvement Act, updating various provisions related to evaluation, eligibility, and procedural safeguards, but preserving the fundamental structure of both rights and the unreached funding commitment.
The Actual Federal Funding Level
In the 2024 fiscal year, Congress appropriated $14.2 billion in IDEA Part B grants to states. According to a Congressional Research Service analysis cited by Education Week, that appropriation was equivalent to 10.9 percent of the average per-pupil expenditure — less than one-quarter of the promised 40 percent level.
The Foundation for Research on Equal Opportunity calculates that meeting the 40 percent commitment would require more than $40 billion annually at current per-pupil costs. The gap between the $14 billion actually appropriated and the $40-plus billion that would fulfill the commitment represents the burden that states and local districts have absorbed over decades.
The National Council on Disability’s “Broken Promises” report documents the historical trajectory in detail: in the period from 1988 through 2017, federal funding for IDEA Part B for students ages 3-21 was funded above 18 percent only once. For most of the past decade, it has remained flat at approximately 15-17 percent, and Brookings notes that as of 2025, IDEA funding offsets an estimated 12 percent of what states and districts actually spend on special education.
The gap between authorization and appropriation is not a technicality. It is the annual difference between what Congress committed to pay and what it has actually provided — a gap that has been transferred entirely to states and school districts.
How Districts Absorb the Shortfall
When federal IDEA funds cover only 10-12 percent of special education costs, and state special education appropriations cover additional but still insufficient amounts, the remaining burden falls on district general operating funds. This is not a one-time emergency measure — it is a structural feature of how special education is financed in practice.
The consequences are direct. Districts facing unfunded special education costs must draw from the same general revenue that supports general education programs: staffing, materials, extracurricular activities, technology, and building maintenance. Every dollar transferred to cover the federal shortfall is a dollar not available for the broader student population.
The Education Law Center’s analysis of Wisconsin provides specific documentation. Wisconsin’s low reimbursement rate for special education left school districts responsible for $1.25 billion in unfunded special education costs in the 2019-2020 school year. High-poverty districts were forced to divert $1,818 per pupil from their general fund to subsidize the state’s underfunding of special education, compared to $1,266 per pupil in the lowest-poverty districts.
This pattern — where high-poverty districts absorb a disproportionate share of the special education funding gap because they tend to have higher rates of students with disabilities — represents a compounding inequity. The districts with the greatest general education resource constraints are simultaneously the districts with the highest unfunded special education obligations.
The NEA’s IDEA Funding Gaps tool provides a state-by-state and district-by-district view of how the funding shortfall is distributed. The tool makes visible what aggregate national figures obscure: the gap is not evenly distributed, and it falls most heavily on the districts least equipped to absorb it.
What Maintenance of Effort Does and Does Not Protect
IDEA includes a “maintenance of effort” (MOE) requirement designed to prevent states and districts from using federal IDEA funds as a replacement for their own spending. Under the requirement, states must budget and spend at least the same amount of state and local funds for special education year over year as a condition of receiving IDEA grants. If a state cuts its special education appropriation below the prior year’s level, the federal government will reduce the state’s IDEA allocation by the difference in the following year.
MOE has had genuine protective effects. New America’s analysis of state responses to budget shortfalls during the recession period found that many states maintained their special education funding by making steeper cuts elsewhere in their budgets, indicating that the provision created real pressure to prioritize special education funding relative to other budget lines.
What MOE does not protect is the adequacy of spending levels. The requirement is to maintain prior-year spending, not to spend at a level that meets student need. If a state was already substantially underfunding special education before MOE applies, the requirement locks in insufficiency. States can apply for waivers from MOE requirements when exceptional or uncontrollable circumstances prevent compliance, adding flexibility that can work against the provision’s intent during budget crises.
MOE also applies at the district level, requiring districts to maintain prior-year local and state special education expenditures to retain their IDEA allocations. Districts that reduce spending can face loss of federal funds — a significant deterrent, but one that operates against a baseline that may itself be inadequate.
Documented Effects on Special Education Students
The chronic underfunding of IDEA produces documented effects on the services students with disabilities receive. The AUCD Policy Talk analysis identifies a range of documented deficits: inadequate individualized services, insufficient staffing (including speech-language pathologists, occupational therapists, and instructional aides), limited access to assistive technology, and reduced transition planning services for students approaching adulthood.
The National Council on Disability’s report notes that the failure to provide adequate federal IDEA funds “has stressed many state and local budgets to the point where many districts routinely struggle to meet student needs.” IDEA’s legal entitlement structure requires districts to provide services defined in each student’s Individualized Education Program (IEP) — but the resources to do so are not guaranteed to match those legal obligations. Families who want to enforce their children’s rights must in many cases hire attorneys, a barrier that the DC Advisory Committee to the U.S. Commission on Civil Rights found places students from less-affluent households at a clear disadvantage.
The teacher shortage in special education compounds the resource gap. Special education remains the most commonly reported shortage area: 45 states identified special education as a shortage area in 2024-25, making it the most consistently underserved teaching field in the country. Districts unable to attract and retain certified special education teachers may assign general education teachers to these roles with inadequate preparation, or leave positions vacant, both of which reduce the quality of services that students with disabilities are legally entitled to receive.
Effects on General Education Students
The diversion of general education funds to cover the special education shortfall creates effects that extend across the student population. When a district transfers $1.5 million from its general operating budget to fund unfunded special education mandates, that money is unavailable for class-size reduction, librarians, art and music instruction, or any of the other programs that benefit all students.
This dynamic creates conditions in which special education funding becomes a point of resentment in school communities, even though the legal obligation to serve students with disabilities is federal and non-waivable. The structural underfunding — not the presence of students with disabilities — is the cause of the resource pressure, but that distinction is often lost in local budget debates.
Underfunded special education also disproportionately affects high-poverty districts, which already operate with fewer discretionary resources. The double burden — serving a higher proportion of students with disabilities while having less general revenue to absorb the unfunded mandate — means that the funding gap compounds the existing resource inequality between districts.
Authorization vs. Appropriation: The Structural Gap
Understanding the IDEA funding gap requires distinguishing between authorization and appropriation. The authorization language in IDEA establishes the formula — 40 percent of average per-pupil expenditure — and the legal entitlement it creates. Appropriations are the actual annual funding decisions made by Congress, which may bear little relationship to what the authorization promises.
This structure is not unique to IDEA, but the consequences are particularly significant because the law creates legally enforceable rights without guaranteeing the resources to fulfill them. Bipartisan groups in Congress have repeatedly introduced legislation to fully fund IDEA — most recently, legislation proposed in 2025 that would mandate gradual increases over 10 years, reaching 40 percent by 2035. None of these proposals has advanced to a vote, leaving the gap that has accumulated since 1975 in place.
This article was researched and drafted with AI assistance under human review. See our full AI and editorial practices.