Developing the educators who change student outcomes.

Part B is the section of IDEA that governs every public school's obligation to ages 3 through 21. It is where FAPE is defined, where the IEP requirements live, where Least Restrictive Environment is named, and where the procedural safeguards families rely on are codified. When educators say "IEP law," they almost always mean Part B.

Part A is the "why" behind everything IDEA does. It is where Congress states the law's purpose — and where it admits the system has fallen short. The 2004 reauthorization explicitly named "low expectations" and "an insufficient focus on applying replicable research" as the barriers blocking children with disabilities from genuine educational opportunity.

Part C covers birth through age 2 — IFSPs, natural environments, family-centered services delivered in the home or community rather than the school. The Part C-to-Part B transition at age 3 is one of the most common compliance gaps in districts serving preschool-age children. IEP Builder supports that handoff.

Part D funds the federal infrastructure: state personnel-development grants, technology demonstration, parent training centers, and the research base that produced the 22 High-Leverage Practices in Special Education. The Lab does not receive Part D funds — but Part D describes exactly the kind of professional-learning infrastructure the Lab is building independently.

The ADA provides civil-rights protection beyond IDEA — covering all public services, programs, and activities. Schools must meet ADA obligations even when a student does not qualify for an IEP. Title II reaches further than IDEA's eligibility categories: it asks whether a student is being excluded from the benefits of a public program because of disability, full stop.

Section 504 is the parallel track — broader than IDEA, with a lower eligibility threshold. A 504 plan can support a student who has a disability that substantially limits a major life activity but who does not need specially designed instruction. It is the original federal disability-rights statute, predating IDEA by two years.