DOT FMCSA defines a Commercial Motor Vehicle (CMV) where the employer and CDL driver are subject to DOT drug testing regulations.
Commercial motor vehicle (CMV) means a motor vehicle or combination of motor vehicles used in commerce to transport passengers or property if the vehicle:
(1) Has gross combination weight rating of 26,001 or more pounds (11,794 or more kilograms) inclusive of a towed unit with a gross vehicle weight rating of more than 10,000 pounds (4,536 kilograms); or
(2) Has a gross vehicle weight rating of 26,001 or more pounds (11,794 or more kilograms); or
(3) Is designed to transport 16 or more passengers, including the driver; or
(4) Is of any size and is used in the transportation of materials found to be hazardous for the purposes of the Hazardous Materials Transportation Act (49 U.S.C. 5103(b)) and which require the motor vehicle to be placarded under the Hazardous Materials Regulations, 49 CFR part 172, Subpart F.