MRO Responsibilities

The Medical Review Officer must be a licensed physician who has knowledge of substance abuse disorders, and has training to evaluate and interpret positive drug test results.


  • Receive negative and positive results from the laboratory
  • Review chain of custody documentation
  • Review and interpret each confirmed positive test result
  • Provide an opportunity for employee to discuss positive test result
  • Review employee’s medical history as appropriate
  • Process employee’s request for retest
  • Notify employer of verified positive test
  • Make return-to-duty or hire recommendations with respect to substance abuse issues

Please note, this is just a general guideline of MRO responsibilities. Specific duties will vary with each MRO.

The Department of Transportation rules require all Medical Review Officers, who review federal drug test results, to be currently certified by a nationally-recognized MRO certification board.