CDL Class A, B, and C: Weight Ratings and What Each License Covers

The three federal CDL groups in one table

Federal rules sort commercial motor vehicles into three groups, and a state's Class A, B and C licenses follow them (49 CFR 383.91). Two numbers do most of the work: 26,001 lb and 10,000 lb.

For Class C, "hazardous materials" means material that must be placarded under 49 CFR Part 172, Subpart F, or any quantity of a listed select agent or toxin (383.5). A small truck with a load that does not need placards is not a Class C vehicle for that reason alone.

The groups nest. A driver who passed the Class A tests may drive Class B and C vehicles, and a Class B driver may drive Class C vehicles, provided they hold any endorsement the vehicle needs (383.91(c)). The rules apply to vehicles used in commerce, and a state may exempt some drivers, such as certain farm and emergency vehicle operators (383.3(d)).

Weight ratings set the CDL class, and actual weight can only raise it

Two ratings decide the class:

• GVWR (gross vehicle weight rating) is the manufacturer's loaded weight for a single vehicle (383.5).
• GCWR (gross combination weight rating) is the greater of the power unit's combination rating, if it appears on the federal certification label, or the sum of the ratings of the power unit and everything it tows (383.5).

The group definitions in 383.91 use these ratings, and so does the skills test. Whether a vehicle is representative of your class is judged by its GVWR or GCWR, "not the vehicle's actual gross vehicle weight" (383.133(c)(3)). An empty tractor-trailer is still a Class A vehicle.

The federal definition of a commercial motor vehicle adds one more check: it counts the rating or the actual weight, whichever is greater (383.5). So running light never shrinks a vehicle's class, while loading a vehicle beyond its rating can pull it into a group its rating alone would miss.

Three worked rigs and the CDL class each needs

The rigs below are made up for practice. Read each rating from the vehicle's certification labels, not from a sales brochure.

Rig 1: a box truck, then the same truck with trailers. The truck is rated 30,000 lb.

• Alone, it is a single vehicle over 26,000 lb, so it needs Class B.
• Towing a trailer rated 8,000 lb, it is still Class B. The total is 38,000 lb, but the towed unit is not over 10,000 lb.
• Towing a trailer rated 12,000 lb, it becomes Class A. The total is 42,000 lb, and the towed unit is now over 10,000 lb.

Rig 2: a heavy pickup with a gooseneck trailer. The pickup is rated 14,000 lb, its certification label lists a GCWR of 37,000 lb, and the trailer is rated 12,000 lb.

• The pickup alone is far below 26,001 lb, so it is not a Class B vehicle.
• The two ratings add up to only 26,000 lb, which is not over 26,000. But GCWR is the greater of the label value and that sum, so this rig's GCWR is 37,000 lb, and the trailer is rated over 10,000 lb. Used in commerce, this rig is Class A.
• Swap in a trailer rated 10,000 lb, and it is no longer Class A, because the towed unit is not over 10,000 lb. Unless it hauls placarded hazardous materials or is designed to carry 16 or more people, it is not a Class C vehicle either.

This is the trap: a pickup does not look like a Class A vehicle, but its label GCWR and the trailer's rating can make it one. Check the pickup's certification label. If it lists a combination rating higher than the sum of the two GVWRs, the higher number is the GCWR. If the label shows no combination rating, the GCWR is the sum of the ratings (383.5).

Rig 3: two passenger vehicles. A shuttle bus rated 18,000 lb is designed to carry 20 people, including the driver. It fails the weight tests for A and B but is designed for 16 or more people, so it needs Class C with a passenger endorsement. A motorcoach rated 38,000 lb is Class B with a passenger endorsement, whatever its seat count.

Passenger buses and the M and N CDL restrictions

The passenger endorsement is tied to the class of bus you test in. Take the passenger skills test in a bus that needs a Class B, and the license is restricted from Class A passenger vehicles, code M. Take it in a Class C passenger vehicle, and the license is restricted from Class A and B passenger vehicles, code N (383.95(e) and (f); 383.153). The passenger endorsement guide covers the rest of the P path, and the Passenger and School Bus tests are two of the eight planned for full CDL prep at launch.

CDL age rules: 18 for a permit, 21 for interstate driving

Federal rules let you get a commercial learner's permit at 18 (383.71(a)(1)). To qualify under the federal driver qualification rules in Part 391, which cover interstate driving, you must be at least 21 (391.11(b)(1)). A license limited to driving within one state carries the restriction code K, "Intrastate only" (383.153).

States apply this in their own words. As of October 2026, per FLHSMV, Florida CDL applicants must be at least 18, and those under 21 are restricted to intrastate operation.

How Texas and California word the CDL classes

State license classes follow the federal groups, but the wording can differ. Two examples:

Because of the California case, this guide says "CDL Class C" or "Group C" when it means the commercial class. Confirm your own state's wording in its CDL manual before you pick a class. The knowledge content does not change with the wording: the eight tests planned for full CDL prep follow the federal knowledge areas that every state manual is built on.

Choosing the CDL class to test for

Pick the class for the vehicle you will actually drive, and test in that kind of vehicle. FMCSA's Drivers page notes that taking the skills test in the vehicle type you will drive avoids restrictions on your license. Testing in a combination joined by a pintle hook instead of a fifth wheel, for example, brings the O restriction, no tractor-trailer (383.95(d)). Testing in a vehicle with an automatic transmission brings the E restriction, no manual transmission (383.95(c)).

The class also decides your knowledge tests. Class A applicants take Combination Vehicles on top of General Knowledge, and the knowledge tests by class guide lists the rest. Once you know your list, see how CDL prep planned for launch splits 1,650 questions across those tests. For the order of steps from permit to license, see how to get a CDL.