Requirements for Positives or Refusals: A CDL driver tests positive, or refuses to take, a DOT drug test. What must the driver do to be able to resume operating any type of commercial motor vehicle?

A CDL driver who tests positive on a DOT test or refuses to take a DOT test, must successfully complete the return-to-duty (RTD) process with a DOT qualified substance abuse professional (SAP).  The requirements for the RTD are found in [49 CFR Part 40, Subpart O]