According to the Office for Civil Rights :
Section 504 of the Rehabilitation Act of 1973 is federal legislation designed to protect the civil rights of individuals with disabilities in programs and activities that receive federal funds. Section 504 states that "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 .