A Class A CDL is required for any combination of vehicles with a Gross Combination Weight Rating (GCWR) of 26,001 pounds or more, as long as the towed vehicle(s) have a GVWR greater than 10,000 pounds. This typically includes large rigs such as truck-tractor and semi-trailer combinations. To qualify for a Class A license, applicants must successfully complete a combination vehicle test, which covers vehicle inspection, basic skills, and road skills assessments.