“504” refers to Section 504 of the Rehabilitation Act of 1973 which covers individuals who meet the definition of qualified "handicapped" person.  For example, a child who has or has had a physical or mental impairment that substantially limits a major life activity or is regarded as handicapped by others. (Major life activities include: walking, seeing, hearing, speaking, breathing, learning, working, caring for oneself, and performing manual tasks.)  It is not required that an individual need special education through IDEA to qualify for 504 services.