The Federal Motor Carrier Safety Administration (FMCSA) requires commercial drivers to pass knowledge and skills tests specific to the type of vehicle they will be driving. Vehicle weight is the main factor in deciding if a driver should have a Class A, B or C license. Commercial drivers who operate intrastate, interstate or foreign commerce must hold a commercial driver's license.
Class A
Any driver who operates a combination of tractor and trailer that has a gross weight of 26,001 lbs. or more, or pulls a trailer or trailers that have a gross vehicle weight rating of more than 10,000 lbs., must have a Class A license.
Class B
Driving a vehicle that has a gross vehicle weight rating of 26,001 lbs. or more requires a Class B license. When such a vehicle is towing a trailer, the trailer's gross weight must not exceed 10,000 lbs.
Class C
If a vehicle is capable of transporting the driver and 15 or more people but is not defined as Class A or Class B, the driver must hold a Class C license. Also designated as Class C are vehicles transporting federally qualified hazardous or poisonous materials or select agents.