The following applicable regulations appear in 49 CFR and 14 CFR:
49 CFR Part 40—Procedures for Transportation Workplace Drug Testing Programs
14 CFR:
§ 67.107—First-Class Airman Medical Certificate, Mental.
§ 67.207—Second-Class Airman Medical Certificate, Mental.
§ 67.307—Third-Class Airman Medical Certificate, Mental.
§ 91.147—Passenger carrying flights for compensation or hire.
§ 135.1—Applicability