Post-Accident Drug Testing Decision Tree
Reviewed August 2026
FMCSA Post-Accident Testing: A Quick Employer Guide
DOT post-accident drug and alcohol testing is required only under specific circumstances. Use the decision tree below to help determine whether testing is required under 49 CFR 382.303.
When Testing Is Required
Human FatalityTesting is required whether or not the commercial motor vehicle driver receives a citation.
Immediate Medical TreatmentTesting is required when bodily injury requires treatment away from the scene and the driver receives a moving-violation citation.
Disabling Vehicle DamageTesting is required when a vehicle must be towed and the driver receives a moving-violation citation.
Required testing timeframes
- Alcohol: Test as soon as practicable. If testing is not completed within two hours, document the reason and continue attempts for up to eight hours.
- Controlled substances: Test as soon as practicable and within 32 hours. After 32 hours, stop attempts and document why the test was not completed.
Non-DOT post-accident testing is governed by the employer’s written drug and alcohol testing policy and applicable law. DOT and non-DOT testing requirements should not be treated as interchangeable.
Need help determining whether a test is required? Call MedScreens at 601-939-3030.
This resource provides general information and is not legal advice. Employers should consult current FMCSA guidance and 49 CFR 382.303 guidance when making testing decisions.