The Americans with Disabilities Act of 1990 (ADA) and now the 2008 ADA Amendments Act (ADAAA) provide the civil rights guarantee for persons with disabilities in the United States. The ADAAA provides protection from discrimination for individuals on the basis of disability. It is not intended to afford anyone special privileges. The ADAAA upholds and extends the standards of compliance set forth in Section 504 of the Rehabilitation Act of 1973 to employment practices, communications, and all policies, procedures and practices that impact the treatment of students with disabilities.
The ADAAA defines a disability as a physical or mental impairment that substantially limits one or more major life activities; has a record of a physical or mental impairment that substantially limits a major life activity or is regarded as having such an impairment.
Not everyone with an "impairment" is disabled; only those whose impairments rise to the level of "substantial limitation" are qualified as disabled.