A chronic mental/cognitive and/or physical impairment incurred before the age of 22 that is likely to continue indefinitely. The disability may substantially impact independent functioning and may require life-long support. The term includes people with mental retardation, cerebral palsy, epilepsy, autism, and sensory impairments. These impairments may have been present from birth or may have resulted from a traumatic accident. Although this is the federal definition, some states or other organizations serving people with developmental disabilities may use a broader or narrower definition to include those they are able to serve.