The Individuals with Disabilities Education Act (IDEA) is the nation’s federal special education law that ensures public schools serve the educational needs of students with disabilities. IDEA requires that schools provide special education services to eligible students as outlined in a student’s Individualized Education Program (IEP). IDEA also provides very specific requirements to guarantee a Free Appropriate Public Education (FAPE) for students with disabilities in the least restrictive environment (LRE). FAPE and LRE are the protected rights of every eligible child, in all fifty states and U.S. Territories.
Excerpt from: http://www.ncld.org/disability-advocacy/learn-ld-laws/idea/what-is-idea