For purposes of this chapter, the term “individual with a disability” does not include an individual who is currently engaging in the illegal use of drugs, when the covered entity acts on the basis of such use.
Notwithstanding subsection (a) and section 12211(b)(3) of this title, an individual shall not be denied health services, or services provided in connection with drug rehabilitation, on the basis of the current illegal use of drugs if the individual is otherwise entitled to such services.
The term “drug” means a controlled substance, as defined in schedules I through V of section 202 of the Controlled Substances Act [21 U.S.C. 812].