The classes of CDL, and commercial motor vehicles they authorize the operation of, are as follows:
- Class A – any combination of vehicles with a combined gross vehicle weight rating of twenty-six thousand one pounds or more, if the gross vehicle weight rating of the vehicle or vehicles being towed is in excess of ten thousand pounds.
- Class B – any single vehicle with a gross vehicle weight rating of twenty-six thousand one pounds or more, or any such vehicle towing a vehicle having a gross vehicle weight rating that is not in excess of ten thousand pounds.
- Class C – any single vehicle, or combination of vehicles, that is not a Class A or Class B vehicle, but that is designed to transport sixteen or more passengers, including the driver, or is transporting hazardous materials in an amount requiring placarding, or any school bus with a gross vehicle weight rating of less than twenty-six thousand one pounds that is designed to transport fewer than sixteen passengers including the driver.
The higher-class CDL allows you to drive vehicles in any of the lower classes provided you have the correct endorsements. Occasional drivers (for example, mechanics or truck salespeople who test-drive CDL vehicles on public roadways) also are required to apply for a CDL and all appropriate endorsements.
In addition to a CDL, drivers may need special endorsements if they:
- drive vehicles carrying passengers (buses);
- pull double or triple trailers (see following section on exemptions);
- drive tank vehicles (see following section on exemptions); or
- haul placarded hazardous materials (see following section on exemptions).