Children
Children refers to individuals from birth to the age of 21 (or such age of majority as provided under State law) including infants, children, youth, adolescents, and young adults.
Source
45 CFR § 1357.10
Scoping language
Scope. This part applies to State and Indian Tribal programs for child welfare services under subpart 1, and family preservation and family support services under subpart 2 of title IV-B of the Act.