According to the Office for Civil Rights:
Section 504 is a federal law designed to protect the rights of individuals with disabilities in programs and activities that receive Federal financial assistance from the U.S. Department of Education (ED). Section 504 provides: "No otherwise qualified individual with a disability in the United States . . . shall, solely by reason of her or his disability, be excluded from the participation in, be denied the benefits of, or be subjected to discrimination under any program or activity receiving Federal financial assistance . . . ."
For more information, consult Section 504 of the Rehabilitation Act and Frequently Asked Questions about Section 504 and the Education of Children with Disabilities.