Special education funding gaps

When IDEA was passed in 1975, the federal government authorized funding up to 40 percent of the average per-pupil expenditure for each child with a disability. The remainder was to be funded by states and localities. Authorization is not appropriation. In practice, federal IDEA Part B appropriations have funded between 10 and 18 percent of excess cost in any given year, with the recent average around 13 percent. The dollar gap between the 40 percent authorization and the actual appropriation is roughly $25 to $30 billion per year. That gap is borne by states and districts. The IDEA Full Funding Act, repeatedly introduced in Congress, would phase in full federal funding over a decade. It has never passed.

States distribute special education funds to districts using different formulas. Census-based formulas allocate funding based on total district enrollment, on the theory that disability incidence is roughly constant across districts. Weighted formulas allocate based on the number of students with disabilities, sometimes with sub-weights for different categories of disability or service intensity. Census-based formulas are simpler to administer and resistant to over-identification incentives but fail to capture variation in actual need. Weighted formulas capture variation but can create incentives to identify more students. The choice between formulas is consequential and is one of the most direct levers state legislatures can pull.

A small share of students with disabilities account for a large share of special education costs. Students requiring one-on-one paraprofessionals, residential placements, or intensive medical services can cost $100,000 to $500,000 per year. A single such student can destabilize a small district's budget. Some states maintain high-cost risk pools that reimburse districts for costs above a threshold per student. The pools work — they prevent budget shock from determining placement — but they are inconsistently funded. States without risk pools push costs back onto districts, which push them onto placement decisions, which fall on the families of the highest-need children.

IDEA's maintenance of effort rule requires districts to spend at least as much on special education each year as they did the previous year (with some exceptions). The rule is designed to prevent districts from using federal IDEA funds to supplant rather than supplement local spending. Enforcement is uneven. Some districts have been found in violation; the typical remedy is a requirement to restore the funding, which is not always backstopped by federal intervention. The rule is a partial protection against erosion of local commitment but does not address the original funding gap.

IEPs commonly specify related services: speech-language pathology, occupational therapy, physical therapy, counseling, behavioral support, audiology, vision services. The services require qualified staff. The supply of qualified staff is constrained — speech-language pathologists, school psychologists, and special education teachers are all in chronic shortage. Districts unable to hire fall back on contracted services, telehealth, or under-staffed in-house programs. The result is that the services specified in the IEP are sometimes not delivered, not because the district refuses but because the staff is not available. The compliance framework does not have a good response to genuine supply shortages, and the burden falls on families.

When a district cannot serve a child in-district, the alternative is private placement at district expense. Private placements for students with disabilities — including out-of-district day programs and residential schools — can cost $80,000 to $250,000 per year. Districts resist private placements because of the cost; parents pursue them through due process when in-district services are inadequate. The result is a system where parents with the resources to litigate secure private placements, and parents without the resources accept in-district services regardless of quality. The pressure valve releases for a thin slice of families and not for the rest.

Charter schools, as a category, have historically under-enrolled students with disabilities relative to their surrounding districts, and have under-served the students with disabilities they do enroll. The pattern reflects a combination of recruitment practices, "counseling out" of students with significant needs, and limited capacity to serve high-cost students within charter funding models. Some charter networks have changed practice, but the structural issue persists: charter funding formulas typically pass through per-pupil amounts without the weighted adjustments that capture special education cost intensity, so charters that enroll high-need students face acute fiscal pressure. The charter sector's growth has reshaped special education in many cities without resolving the funding problem.

The funding structure creates competing incentives around identification. A weighted funding formula incentivizes identification (more identified students, more funding). The cost of services incentivizes under-identification (each identified student adds cost beyond what the formula captures). State accountability systems that measure outcomes for students with disabilities incentivize identifying students who will perform well in the disability subgroup. Federal monitoring of significant disproportionality requires districts to investigate over-identification of students of color in certain categories. The interaction of these incentives produces identification patterns that do not cleanly reflect underlying disability prevalence; they reflect the budget and accountability structure surrounding identification.

Students from low-income families are identified for special education at substantially higher rates than students from higher-income families, with the gap concentrated in certain categories (emotional disturbance, intellectual disability). The overlap reflects underlying biological factors — prenatal exposures, lead exposure, premature birth, inadequate nutrition — and also social factors — under-resourced early childhood education, less access to early intervention, school environments less able to support diverse learning needs. The funding structure compounds the overlap: the districts with the highest needs are the districts with the weakest fiscal capacity. A federal funding system that addressed this would direct more resources to higher-need districts. The current system does so partially through Title I and through IDEA grants, but not enough to close the resource gap.

IDEA Part C funds early intervention services for children from birth to age three. Services are typically delivered in the home or community by therapists contracted through state agencies. At age three, eligible children transition to Part B school-based services. The transition is often rocky: services that were available at home are not always available at school, eligibility criteria shift, and parents who navigated one system have to learn another. Investment in Part C has well-documented long-term returns — better outcomes, lower lifetime costs — but Part C is consistently under-funded relative to need. The early childhood window is when intervention is most effective, and it is also when the funding is thinnest.

The variation between states in special education funding, identification rates, placement patterns, and outcomes provides natural-experiment evidence on what works. States with weighted funding formulas, high-cost risk pools, and integrated Part C-to-Part B transitions produce better outcomes on most measures. States with census-based formulas, no risk pools, and segmented service systems produce worse outcomes. The evidence is available and is used in state policy debates, but the diffusion of best practice is slow. The dominant variable is fiscal capacity, not policy knowledge.

The political economy of IDEA full funding has been stable for decades: bipartisan rhetorical support, no enactment. The reasons include the size of the appropriation required, competing priorities, and the dispersed political constituency for special education. The constituency is dispersed because it cuts across geography, party, race, and class. Disability is universally distributed in a way that makes coalition-building difficult — the parent of a child with autism in a wealthy suburb and the parent of a child with emotional disturbance in a poor city have legitimate but different interests. The disability rights movement has been most successful when it has built broad coalitions and least successful when its different constituencies have split. Full funding of IDEA is a coalition project that has not yet found its coalition.

A planned funding system would: enact full federal funding of the 40 percent authorization, phased over five to seven years; require states to use weighted funding formulas with sub-weights by intensity of need; establish federal and state high-cost risk pools to backstop catastrophic costs; separate special education funding from general education funding to prevent quiet supplantation; tie a portion of funding to measured outcomes (graduation rates, postsecondary participation, employment) alongside compliance; invest in Part C early intervention at levels that match the long-term return; address workforce shortages through federal scholarship and loan-repayment programs for special education staff; and provide federal funding for parent advocacy infrastructure so that procedural rights translate into substantive outcomes regardless of family income. The package is large but each piece is feasible. The collective failure is not technical; it is political. Law 4 says: design from outcomes. The current funding system was not designed from outcomes. It was negotiated from the original 1975 compromise and has been preserved by inertia ever since.

1. National Council on Disability, Broken Promises: The Underfunding of IDEA (Washington, DC: NCD, 2018). 2. Thomas Parrish and Jay G. Chambers, "Financing Special Education," The Future of Children 6, no. 1 (1996): 121–138. 3. U.S. Department of Education, 44th Annual Report to Congress on the Implementation of the Individuals with Disabilities Education Act (Washington, DC: Office of Special Education Programs, 2022). 4. Eloise Pasachoff, "Special Education, Poverty, and the Limits of Private Enforcement," Notre Dame Law Review 86, no. 4 (2011): 1413–1492. 5. Mary Wagner, Lynn Newman, Renée Cameto, and Phyllis Levine, Changes Over Time in the Early Postschool Outcomes of Youth with Disabilities (Menlo Park, CA: SRI International, 2005). 6. Bruce D. Baker and Sean P. Corcoran, The Stealth Inequities of School Funding: How State and Local School Finance Systems Perpetuate Inequitable Student Spending (Washington, DC: Center for American Progress, 2012). 7. Center for American Progress, A Quality Approach to School Funding: Lessons Learned from School Finance Litigation (Washington, DC: CAP, 2018). 8. Nora Gordon, "Do Federal Grants Boost School Spending? Evidence from Title I," Journal of Public Economics 88, no. 9–10 (2004): 1771–1792. 9. Jay G. Chambers, Thomas B. Parrish, and Jenifer J. Harr, What Are We Spending on Special Education Services in the United States, 1999–2000? Special Education Expenditure Project Report 1 (Palo Alto, CA: American Institutes for Research, 2004). 10. Perry A. Zirkel, "Special Education Law: Illustrative Basics and Nuances of Key IDEA Components," Teacher Education and Special Education 38, no. 4 (2015): 263–275. 11. Individuals with Disabilities Education Act, 20 U.S.C. §§ 1400 et seq. 12. Council for Exceptional Children, Special Education Funding Issues: A Position Paper (Arlington, VA: CEC, 2019).