No — RTD testing is completed before returning to duty. Follow-up testing occurs after.
Regulatory
Compliance.
- 49 CFR Part 40 – DOT Drug & Alcohol Testing Procedures
- 49 CFR Part 382 – FMCSA Drug & Alcohol Regulations
- DOT SAP & Return-to-Duty Requirements
Drivers may not perform safety-sensitive functions until a verified RTD test is completed
and documented.

