DOT Rule 49 CFR Part 40 Section 40.165
Subpart G - Medical Review Officers and the Verification Process
§ 40.165 To whom does the MRO transmit reports of drug test results?
(a) As the MRO, you must report all drug test results to the DER, except in the circumstances provided for in §40.345 .
(b) If the employer elects to receive reports of results through a C/TPA, acting as an intermediary as provided in §40.345, you must report the results through the designated C/TPA.