"When do I need a CDL?
1.A Class A CDL License is required when the Gross Combined Vehicle Weight Ratings (GCVWR) of the truck and trailer totals 26,001 or more provided the GVWR of the vehicle(s) being towed is in excess of 10,000 pounds.
2.A Class B CDL License is required for any single vehicle with a GVWR of 26,001 or more pounds, or any such vehicle towing a vehicle not in excess of 10,000 pounds GVWR.
3. A Class C CDL License is required for any single vehicle, or combination of vehicles, that does not meet the definition of Class A or Class B, but is either designed to transport 16 or more passengers, including the driver, or is placarded for hazardous materials.
One of the most misunderstood parts of the above requirements has to do with trailers with a GVWR in excess of 10,000 pounds when the combined GVWR does not exceed 26,000 pounds. In this case a CDL is NOT required provided you are not placarded for hazardous materials. However individual states may impose a requirement that drivers in their states must have a CDL in this situation so you need to check the requirements in your state. It is also important to note that individual state CDL licensing requirements CAN NOT be applied to drivers from other states."