DOT Drug Test
A required test for controlled substances that CDL drivers must pass before employment, after accidents, and at random under 49 CFR Part 382.
DOT drug tests screen for 5 substance categories: marijuana metabolites, cocaine metabolites, opioids, amphetamines, and phencyclidine (PCP). Tests are conducted via urine sample at a certified collection site. The urinalysis in the DOT physical is separate — it checks for glucose and protein, not drugs. A positive result must be reported to the FMCSA Clearinghouse. The driver cannot return to safety-sensitive duties until completing the Return-to-Duty (RTD) process.
Types of required DOT drug tests
Five testing situations are required under 49 CFR Part 382: (1) pre-employment — required before first safety-sensitive duty, must be negative; (2) random — unannounced selection from a compliant pool throughout the year; (3) post-accident — after certain DOT-recordable accidents meeting specific criteria (fatalities; citations with towing; bodily injury requiring off-site medical treatment); (4) reasonable suspicion — when a trained supervisor has documented grounds to believe impairment; and (5) return-to-duty and follow-up — after a violation, through the SAP process.
Consequences of a positive DOT drug test
A confirmed positive DOT drug test immediately removes the driver from all safety-sensitive duties. The Medical Review Officer (MRO) reports the positive result directly to the FMCSA Clearinghouse. The driver's Clearinghouse status becomes "prohibited." The driver cannot return to safety-sensitive work until completing the full return-to-duty process: SAP evaluation, recommended treatment or education, a negative RTD drug test, and subsequent follow-up testing (minimum 6 tests over the next 12 months). The violation record remains in the Clearinghouse until RTD is complete.
Last updated: May 28, 2026
When this definition matters
This term usually matters when a driver, owner-operator, or small carrier is deciding whether a federal rule applies, preparing a compliance file, or checking a state CDL step. Use this definition as a starting point, then confirm the controlling requirement in the official source listed below before making a licensing, hiring, dispatch, or recordkeeping decision.
The related terms above are included because they often appear in the same compliance workflow. Reviewing them together can prevent common mix-ups, such as treating a state licensing step as a federal carrier obligation or confusing a driver record with a separate employer record.