CDL drivers who operate vehicles subject to federal CDL requirements on public roads generally perform safety-sensitive functions and are covered by DOT drug and alcohol testing rules. Coverage includes full-time, part-time, intermittent, backup, and many self-employed drivers.
When testing can occur
- Pre-employment: the employer generally must receive a verified negative controlled-substances result before allowing the driver to operate a covered CMV.
- Random: covered drivers remain in a compliant random testing pool.
- Post-accident: testing depends on the crash outcome and, in some cases, whether the CMV driver received a citation.
- Reasonable suspicion: trained supervisors may require testing based on specific observations.
- Return-to-duty and follow-up: these apply after a violation and completion of the substance abuse professional process.
What the Clearinghouse records
The FMCSA Drug and Alcohol Clearinghouse is the federal database for violations of the drug and alcohol testing program and the driver's return-to-duty status. Employers must conduct required queries before hiring and during employment. Drivers should keep their account information current and review the record for accuracy.
What a prohibited status means
A driver in prohibited status may not perform a safety-sensitive function, including operating a CMV that requires a CDL. Under Clearinghouse-II, state licensing agencies also receive status information and must complete a CDL or CLP downgrade within the federal process. Changing employers or moving to another state does not erase the status.
Return-to-duty overview
- Select a qualified substance abuse professional in the Clearinghouse.
- Complete the professional's education or treatment recommendations.
- Complete the follow-up evaluation.
- Receive a negative return-to-duty test arranged by a current or prospective employer.
- Complete the follow-up testing plan while performing safety-sensitive work.
The precise steps and timing depend on the individual case. A driver cannot self-order the return-to-duty test and treat it as clearance to drive.
Before applying to a CDL job
- Confirm that your CDL and medical certification are current.
- Log in to the Clearinghouse and verify your contact details.
- Respond promptly to an employer's electronic query consent request.
- Disclose information truthfully on the application.
- Do not drive a covered CMV until the employer confirms all pre-employment requirements are complete.
Testing and Clearinghouse checks are only part of driver qualification. Use the CDL licensing guide and medical certification guide to review the other federal steps.