When is post-accident testing required?
For covered CDL drivers, not every crash requires an FMCSA post-accident drug and alcohol test. The employer must evaluate the accident type, treatment or towing outcome and whether the driver received a qualifying citation.
Updated July 24, 2026 • Educational information, not legal adviceCall promptly after an incident. The employer—not the collection site—determines whether testing is required. Test First can help coordinate the ordered collection after the employer identifies the test authority and reason.
FMCSA testing trigger summary
Timing and documentation
Test as soon as practicable
Once the employer determines that testing is required, it should arrange the drug and alcohol tests promptly while following the applicable rule.
Alcohol documentation
If an alcohol test is not completed within two hours, the employer must prepare and maintain a record explaining the delay. Attempts cease after eight hours.
Drug-test documentation
If the controlled-substances test is not completed within 32 hours, attempts cease and the employer must document why it was not administered.
A practical employer response sequence
- 1
Protect people and address the emergency
Emergency care, law-enforcement instructions and scene safety come first.
- 2
Notify the designated employer representative
Provide the known facts without waiting for assumptions or informal conclusions.
- 3
Apply the FMCSA testing table
Determine whether the accident and citation facts trigger drug testing, alcohol testing or both.
- 4
Direct the driver and arrange collection
Give clear instructions, preserve contact and identify the collection site or mobile response option.
- 5
Record timing, attempts and delays
Preserve the accident facts, testing decision, contacts, collection timing and reasons for any delay or missed test.
Official sources
Confirm the current rule and interpretations before making a compliance decision.