DOT testing for marijuana continues
DOT continues to include marijuana in its regulated drug-testing program. The Department's current marijuana notice says transportation employees in safety-sensitive positions remain subject to marijuana testing and that laboratories, Medical Review Officers and Substance Abuse Professionals must continue following 49 CFR Part 40. See the DOT marijuana notice.
Federal marijuana scheduling changed in part during 2026, including certain FDA-approved products and products subject to qualifying state medical-marijuana licensing. That did not create a general exemption from DOT testing.
State-authorized marijuana does not make a DOT positive negative
DOT issued updated authoritative MRO guidance in May 2026 after the federal scheduling changes. It states that an MRO cannot verify a laboratory-confirmed marijuana positive as negative merely because the employee says the result came from marijuana obtained through a state-licensed program. State medical-marijuana cards, recommendations and dispensary records do not by themselves establish the legitimate medical explanation required under Part 40.
The current DOT Q&A is available at 49 CFR §§40.137, 40.141 and 40.151 Q&A. Recreational legality under state law likewise does not override the DOT testing requirements.
CBD creates a different problem
DOT testing is for marijuana metabolites, not CBD itself. However, DOT has warned that CBD products may contain enough THC to result in a positive marijuana test and that CBD use is not an acceptable explanation for reversing a laboratory-confirmed marijuana positive. The Department's CBD notice advises DOT-regulated safety-sensitive employees to exercise caution.
There is no reliable website calculation that can tell you whether a particular CBD product, dose or period of abstinence will produce a negative DOT result. Trying to time or manipulate a test is not a substitute for complying with the testing process.
What happens after a verified DOT marijuana positive
A verified positive DOT drug test is a violation under §40.285. The employee must be removed from DOT safety-sensitive duties and cannot resume those duties until completing the required SAP process and subsequent return-to-duty requirements.
For CDL drivers subject to FMCSA rules, the violation is also relevant to Drug and Alcohol Clearinghouse status. See Clearinghouse prohibited status and failed DOT drug test guidance for those next steps. Neither state legality nor completing a SAP evaluation by itself clears the violation.