29 CFR Part 1630, Regulations to Implement the Equal Employment Provisions of the ADA (Title I Regulations with amendments issued through May 2016)

(b) However, the terms disability and qualified individual with a disability may not exclude an individual who:

(1) Has successfully completed a supervised drug rehabilitation program and is no longer engaging in the illegal use of drugs, or has otherwise been rehabilitated successfully and is no longer engaging in the illegal use of drugs; or

(2) Is participating in a supervised rehabilitation program and is no longer engaging in such use; or

(3) Is erroneously regarded as engaging in such use, but is not engaging in such use.