42 U.S. Code § 12376 - Definitions

For purposes of this subchapter—
the terms “child”, “youth”, and “young individual” means [1] an individual who is less than 21 years of age.

[1]  So in original. Probably should be “mean”.
Effective Date

Section effective Oct. 1, 1990, see section 1001(a) of Pub. L. 101–501, set out as an Effective Date of 1990 Amendment note under section 8621 of this title.