- youth - persons under the age of 21.
- youth center - any recreational facility and/ or gymnasium (including any parking lot appurtenant thereto), intended primarily for use by persons under 18 years of age, which regularly provides athletic, civic, or cultural activities.
- youth offender - an individual who is 21 years of age or younger who has been discharged from a State or local juvenile or criminal justice system, except that if the individual is between the ages of 18 and 21 years, such individual has had contact with the State or local juvenile or criminal justice system prior to attaining 18 years of age and is under the jurisdiction of such a system at the time services are sought.
- youth with a disability - an individual with a disability who — (i) is not younger than 14 years of age; and (ii) is not older than 24 years of age.
- youth with disabilities - more than 1 youth with a disability.
- youth with HIV - individuals who are 13 through 24 years old and who have HIV/ AIDS.