What Each CDL Class Covers

The Federal Motor Carrier Safety Administration (FMCSA) divides commercial driver's licenses into three classes — A, B, and C — based on the vehicle's gross vehicle weight rating (GVWR) and what it's designed to carry. Each class has different training requirements, testing standards, and restrictions on the types of work you can legally perform. Your class determines not just what you can drive, but what cargo you can haul and whether you can operate certain equipment.

Within each class, you may also hold endorsements — additional qualifications that allow you to operate specialized vehicles or transport specific materials. A tanker endorsement, for example, lets you haul liquid cargo in bulk tanks. A hazmat endorsement authorizes you to transport hazardous materials. These endorsements are separate from your class and require their own testing.

Key Takeaways

  • Class A CDLs cover the heaviest vehicles and tractor-trailers, and are required for most long-haul trucking jobs.
  • Class B CDLs are for single vehicles over 26,001 pounds GVWR, such as straight trucks and large buses, and do not allow you to pull trailers.
  • Class C CDLs are for smaller commercial vehicles and are rarely required unless you transport hazmat or passengers in certain configurations.
  • Endorsements like tanker, hazmat, and passenger are added to your class license and require separate written and sometimes practical tests.
  • Your state's DMV issues the CDL, but the FMCSA sets the minimum standards that all states must follow.

Class A: Tractor-Trailers and Heavy Combination Vehicles

A Class A CDL is the most common commercial license for long-haul trucking. It covers any combination of vehicles with a GVWR of 26,001 pounds or more, as long as the trailer or towed vehicle weighs more than 10,000 pounds. This includes tractor-trailers, doubles, and triples. If you want to haul freight across state lines or work for a large trucking company, you almost certainly need a Class A.

To obtain a Class A, you must pass a written knowledge test covering general commercial driving rules, air brakes (if your vehicle has them), and combination vehicles. You also take a skills test that includes a pre-trip inspection, a basic control test, and a road test in an actual tractor-trailer or similar combination vehicle. Many states require you to hold a commercial learner's permit (CLP) for at least 14 days before you can test for the Class A license itself.

A Class A license is the broadest: you can legally operate any commercial vehicle that requires a CDL, including Class B and Class C vehicles. This makes it the most versatile option if you plan to change jobs or want maximum flexibility in your career.

Class B: Straight Trucks and Large Single Vehicles

A Class B CDL covers single vehicles (not combinations) with a GVWR of 26,001 pounds or more. This includes straight trucks, large dump trucks, cement mixers, garbage trucks, and full-size buses. The key difference from Class A is that you cannot pull a trailer or towed vehicle of any significant weight. If the trailer weighs 10,000 pounds or less, you may tow it, but this is rarely practical for commercial work.

The written test for Class B is similar to Class A — general knowledge, air brakes if applicable, and rules specific to the vehicle type. The skills test uses the actual type of vehicle you will drive, such as a straight truck or bus. You do not test in a combination vehicle because you will not be operating one professionally.

Class B is common in local delivery, waste management, and public transit. If you work for a city or county, or for a regional delivery company that uses straight trucks, you likely need a Class B. A Class A license also allows you to drive Class B vehicles, but the reverse is not true.

Class C: Small Commercial Vehicles and Specialized Roles

A Class C CDL covers commercial vehicles that do not fall into Class A or B but still require a commercial license. This typically means vehicles under 26,001 pounds GVWR that transport hazardous materials, or vehicles designed to carry 16 or more passengers (including the driver). In practice, Class C is the rarest of the three because most small commercial vehicles do not require a CDL at all — only a regular driver's license.

You need a Class C CDL if you drive a small bus or van that carries 16 or more people for a school district, senior center, or transit agency, or if you operate a small vehicle that hauls hazmat. The written test covers general commercial rules and any endorsements you need. There is typically no skills test for Class C unless you also hold a passenger or hazmat endorsement, which may require additional testing.

Class C is often a stepping stone for people entering commercial driving who do not yet need the heavier vehicles. It is also used by some employers in niche roles, such as transporting medical waste or operating small charter buses.

Endorsements: Tanker, Hazmat, Passenger, and Others

An endorsement is a notation on your CDL that authorizes you to operate specialized vehicles or transport specific cargo. You can hold multiple endorsements on a single license. The most common are tanker (T), hazmat (H), and passenger (P). Each requires a separate written test, and some require a practical test as well.

A tanker endorsement allows you to haul liquids or gases in bulk tanks. The test covers the physics of liquid surge, proper braking with a full tank, and safety procedures. A hazmat endorsement authorizes you to transport materials classified as hazardous by the Department of Transportation (DOT), such as explosives, flammables, or toxic substances. This endorsement requires a written test and a background check. A passenger endorsement is required if you operate a vehicle designed to carry 16 or more people, and it includes a written test and a practical skills test.

Other endorsements include doubles/triples (for pulling multiple trailers), air brake (required if your vehicle has air brakes), and school bus (for transporting school children). Your state's DMV office can tell you which endorsements are available and which your job requires.

Restrictions and Limitations on Your License

Your CDL may also carry restrictions — limitations on what you can drive or where you can drive it. Common restrictions include "no air brakes" (if you failed the air brake test), "no manual transmission," or "no interstate" (limiting you to in-state driving only). Some states impose restrictions based on medical conditions or vision requirements.

If you hold a Class B license, you are automatically restricted from towing anything over 10,000 pounds, even though you might be able to physically do so. If you hold a Class C license, you are restricted from operating Class A or B vehicles. These restrictions are built into the class itself and do not appear as separate notations on your card.

Restrictions can sometimes be removed by retesting or by providing medical documentation, depending on the reason for the restriction. Your state DMV can explain what restrictions explore to your license and how to challenge them if you believe they were issued in error.

How States Test and Issue Each Class

Every state's DMV administers CDL tests, but the FMCSA sets the minimum standards. This means the written test questions, the skills test procedures, and the medical requirements are largely the same across all 50 states, though some states add their own rules or endorsements.

To obtain any CDL class, you must first pass a medical examination by a certified medical examiner and receive a Medical Certificate (also called a Medical Examiner's Certificate). You then explore for a commercial learner's permit (CLP) by passing a written knowledge test. After holding the CLP for the required waiting period (usually 14 days), you schedule a skills test. The skills test is conducted by a third-party tester — either a state employee or a private testing service approved by your state.

The entire process typically takes 4 to 8 weeks from start to finish, depending on how quickly you can schedule tests and how many attempts you need. Some states allow you to test for multiple classes or endorsements in a single visit, while others require separate appointments.

Frequently Asked Questions

Can I drive a Class B vehicle with a Class A license?

Yes. A Class A license allows you to operate any commercial vehicle that requires a CDL, including Class B and Class C vehicles. However, the reverse is not true — a Class B license does not allow you to drive Class A vehicles.

Do I need a hazmat endorsement to haul any kind of cargo?

No. You need a hazmat endorsement only if you transport materials classified as hazardous by the DOT, such as explosives, flammables, or poisons. Regular freight, food, or consumer goods do not require a hazmat endorsement. Your employer will tell you if the job requires one.

What happens if I fail the CDL skills test?

You can retake the test, usually within a few days or weeks depending on your state's scheduling. There is no limit to how many times you can test, though you may have to pay a fee each time. Many people pass on their second or third attempt.

Can I hold endorsements without holding a CDL class?

No. Endorsements are added to a CDL class — you cannot have an endorsement without first holding a Class A, B, or C license. You must pass the class test before you can test for endorsements.

Does my CDL class change if I get a new job?

No. Your CDL class is permanent until you choose to upgrade or downgrade it. If you move from a job requiring a Class B to a job requiring a Class A, you must test for the Class A license. Your old Class B license remains valid until it expires.