42 U.S. Code § 9919 - Drug and child support services and referrals
Nothing in this chapter shall be construed to prohibit a State from testing participants in programs, activities, or services carried out or provided under this chapter for controlled substances. A State that conducts such testing shall inform the participants who test positive for any of such substances about the availability of treatment or rehabilitation services and refer such participants for appropriate treatment or rehabilitation services.
Any funds provided under this chapter expended for such testing shall be considered to be expended for administrative expenses and shall be subject to the limitation specified in section 9907(b)(2) of this title.
In this subsection, the term “controlled substance” has the meaning given the term in section 802 of title 21.