In order for you to obtain a CDL license, you must determine which type of Commercial Motor Vehicle (CMV) you will be driving. The U.S. Department of Transportation has categorized vehicles into three classes or license groups. In addition to specifying a license group, you will also need to understand if there are specific endorsements that you will need based on the specific type of vehicle you plan on operating. Endorsements cover doubles/triples, Tanks, Hazardous Materials, Passenger Transport and School Buses. Additionally, you will have to determine if your vehicle has Air Brakes which require an additional endorsement.
Group A (Combination Vehicle) CDL License
Any combination of vehicles with a gross combination weight rating (GCWR) of 26,001 pounds or more provided the GVWR of the vehicle(s) being towed is in excess of 10,000 pounds.
You may drive any vehicle or combination of vehicles of any size.
Group B (Heavy Straight Vehicle) CDL License
Any single vehicle with a GVWR of 26,001 pounds or more, or any such vehicle towing a vehicle not in excess of 10,000 pounds GVWR.
You may drive any single vehicle regardless of weight. You may tow a trailer if the trailer’s gross vehicle weight rating (GVWR) is not more than 10,000 pounds. If the trailer you are towing has a GVWR of more than 10,000 pounds, and the combined vehicle weight rating is more than 26,000 pounds, you will need a Class A CDL.
Group C (Small Vehicle) CDL License
Any single vehicle, or combination of vehicles, that meets neither the definition of Group A nor that of Group B, but that either is designed to transport 16 or more passengers including the driver, or is used in the transportation of Hazardous Materials.
You may drive any vehicle designed to transport 16 or more passengers, including the driver, if the GVWR is less than 26,001 pounds and you have a passenger endorsement. A Class C CDL also lets you drive any vehicle used to transport hazardous materials if the GVWR is less than 26,001 pounds and you have the proper endorsement.
For more information, please see the Commercial driver's license standards, requirements and penalties (49 CFR Part 83).