US lawFederal (United States)RegulationsTitle 49 CFR — TransportationChapter III — FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATIONPart 382 — CONTROLLED SUBSTANCES AND ALCOHOL USE AND TESTINGSubpart C — Tests Required382.30949 C.F.R. § 382.309Return-to-duty testing.Last amended: 2016Year: 2026Length: 17 wordsOfficial source Cite as 49 C.F.R. § 382.309 (2026)The requirements for return-to-duty testing must be performed in accordance with 49 CFR part 40, subpart O.Previous49 C.F.R. § 382.307Next49 C.F.R. § 382.311