IDEA's maximum State grant formula uses 40% of national average per-pupil expenditure. A U.S. Department of Education policy explanation states that IDEA does not require Congress to appropriate that maximum.1 The article's table uses a separate estimated excess-cost denominator. The current record does not show that this denominator equals the statutory maximum-allocation formula.
The article lists federal appropriations beside an estimated excess-cost benchmark. The table has not yet been reproduced from a public analysis package, and its former percentage column is withdrawn.
The article defines the difference between the two displayed series as a funding gap. That construction still requires a public derivation of the excess-cost benchmark.
| Fiscal Year | Federal IDEA Funding | Article's Estimated Excess-Cost Benchmark |
|---|---|---|
| 2010 | $11.5 billion | $29.0 billion |
| 2015 | $11.8 billion | $32.4 billion |
| 2020 | $13.0 billion | $36.2 billion |
| 2024 | $14.2 billion | $40.1 billion |
Article-reported federal IDEA Part B funding compared with an estimated national excess-cost benchmark. This is not the statutory 40%-of-APPE formula unless the denominators are shown to align. Sources named in the article: U.S. Department of Education Budget History and AASA special-education expenditure estimates. The table is not publicly reproduced.
What This Shows
The percentage claim is withdrawn. Dividing each displayed appropriation by its displayed excess-cost benchmark does not reproduce the former percentage column. The page does not establish a share of the statutory maximum-allocation formula.
The article reports a growing dollar gap. Reproducing the excess-cost denominator is necessary before treating that trend as verified.
IDEA's maximum State grant formula uses 40% of national average per-pupil expenditure; it does not require Congress to appropriate that maximum. For 2024, the article separately compares $14.2 billion in appropriations with a $40.1 billion estimated excess-cost benchmark. Those estimates are not publicly reproduced, and the two benchmark definitions should not be treated as interchangeable.
The Encroachment Problem
In education finance, we call it "encroachment." Special education costs exceed special education revenue, and the gap must be covered from general funds.2
The displayed article-reported bins imply a weighted average of about 4.2% of general fund budgets, while the highest category begins above 10%. The table and district population are not publicly reproduced.
| Encroachment Level | Share of Districts | Mean General Fund Impact |
|---|---|---|
| Low (<2%) | 28% | 1.2% |
| Moderate (2-5%) | 44% | 3.4% |
| High (5-10%) | 21% | 6.8% |
| Very High (>10%) | 7% | 13.2% |
Encroachment = (SpEd expenditures - SpEd revenue) / General fund expenditures. The previously stated unified-district count is withdrawn; the public materials do not identify the analytic district population. Source named in the article: California SACS financial data, 2018-19.
The Zero-Sum Reality
Encroachment means general-fund dollars are used to cover special education costs beyond designated revenue. The resulting budget tradeoffs depend on each district's choices and constraints.
When special education costs rise faster than designated revenue, districts must decide how to cover the difference. Possible responses can include:
- Larger class sizes
- Fewer counselors and librarians
- Eliminated electives
- Deferred purchases
Who Pays for the Funding Gap
IDEA's protections for students with disabilities remain in place. The debate isn't about removing them.
The question is about costs.
The statute provides a 40%-of-APPE maximum-allocation formula, while the article separately lists appropriations and an estimated excess-cost benchmark. The former percentage column is withdrawn. During budget constraints, a local contribution can grow, but this article does not identify which district programs or revenue sources adjust.
Someone pays for special education. Understanding who helps us think clearly about policy.
Limitations
Self-reported impacts. The encroachment impact data comes from district administrator surveys, which may reflect perceptions rather than documented budget changes.
Causation unclear. Districts facing encroachment pressures may also face other fiscal challenges. We cannot isolate the specific effect of encroachment from general budget constraints.
Cross-state variation. California's special education funding formula differs from other states. Encroachment levels and impacts may vary considerably in other contexts.
Data and Methods
Data sources:
- Federal funding: U.S. Department of Education Budget History tables
- State/local funding: California SACS financial reports
- Encroachment calculations: (Special education expenditures - Special education revenue) / General fund expenditures
- Survey data: California Association of School Business Officials
Sample: The article describes California SACS records for encroachment calculations and 312 CASBO survey respondents. The previously stated unified-district count is withdrawn, and no public analytic file identifies the SACS district population.
Withdrawn percentage calculation: The former percentage column does not equal the displayed IDEA Part B appropriation divided by the displayed estimated national excess-cost benchmark. A reproducible denominator is required before reporting a federal share. This comparison is distinct from the statutory maximum State grant formula based on 40% of national average per-pupil expenditure.
Notes
1 IDEA, 20 U.S.C. §1411(a)(2)(B)(ii), uses 40% of national average per-pupil expenditure in the maximum State grant formula. The U.S. Department of Education has explained that the statute does not require Congress to appropriate each State that maximum.
2 WestEd. (2020). California Special Education Funding System Study, Part 1: A Descriptive Analysis of Special Education Funding in California. California Department of Education. https://www.wested.org/resources/california-special-education-funding-system-study-part-1/
Frequently Asked Questions
What do the article's federal funding figures compare?
IDEA's maximum State grant formula uses 40% of national average per-pupil expenditure. The article separately lists appropriations and an estimated national excess-cost benchmark. Its percentage column does not equal the displayed numerator divided by the displayed denominator, so those percentages are withdrawn pending a reproducible calculation.
How much has the federal funding gap grown?
The article reports an estimated shortfall rising from $17.5 billion in 2010 to $25.9 billion in 2024. The calculation is not publicly reproduced here.
What is encroachment in education finance?
Encroachment describes special education costs exceeding designated special education revenue, with the difference covered from general funds. The displayed article-reported bins imply a weighted average of about 4.2%. The table and district population are not publicly reproduced.
How many California districts face severe encroachment?
The article reports that 7% of California districts had encroachment above 10% of general education resources and that this group averaged 13.2%. These estimates are not publicly reproduced here.
What data sources were used for this analysis?
The article cites U.S. Department of Education budget tables, California SACS reports, and CASBO survey data from a stated 312 respondents. Its previously stated California unified-district count is withdrawn because it does not match the statewide district universe. No matching public analysis package currently identifies the analytic sample or reproduces the estimates.
Suggested Citation
Cholette, V. (2025, December 28). IDEA's funding benchmark and local budgets. Too Early To Say. https://tooearlytosay.com/research/education-policy/unfunded-mandate-special-education/Copy citation