The difference between Class A and Class B licenses

A Class A license lets you drive the largest commercial trucks — typically those with a gross vehicle weight rating (GVWR) of 26,001 pounds or more. A Class B license covers smaller commercial vehicles, usually with a GVWR between 26,001 pounds and those just under the Class A threshold, depending on your state. The key difference is weight and the number of trailers you can pull: Class A drivers can operate tractor-trailers and doubles, while Class B drivers operate single large vehicles like dump trucks, cement mixers, and city buses.

Both are commercial driver's licenses (CDLs), which means they require more training and testing than a regular passenger license. You cannot straightforward upgrade from one to the other — you take the test for the class you need based on the vehicle you will be driving for work. Some states use slightly different weight thresholds or naming conventions, so the exact boundary between Class A and Class B varies by state.

Key Takeaways

  • Class A licenses cover the heaviest commercial vehicles, including tractor-trailers and double trailers, while Class B covers smaller commercial trucks and buses.
  • Both require passing a written knowledge test, a skills test, and a medical examination, plus holding a valid regular driver's license first.
  • You must hold your CDL permit for at least seven days before taking the skills test, and some states require longer waiting periods.
  • The testing process typically takes several weeks from start to finish, and you will need to pass all three components before the license is issued.

What vehicles you can drive with each class

With a Class A license, you can operate any commercial vehicle, including tractor-trailers (the big rigs you see on highways), doubles (a tractor pulling two trailers), and triples in states that allow them. You can also drive anything a Class B driver can drive. This makes Class A the broadest commercial license.

With a Class B license, you can drive single large commercial vehicles: dump trucks, cement mixers, garbage trucks, city buses, and other vehicles over the weight threshold. You cannot pull trailers with a Class B license unless you also hold a trailer endorsement, and even then the rules are more restrictive than Class A. If you only need to drive a dump truck or a bus, Class B is the correct license to pursue.

The testing process for Class A and Class B

Both Class A and Class B require you to pass three separate tests: a written knowledge test, a pre-trip inspection test, and a behind-the-wheel driving test. You must pass all three to receive the license. Most states require you to hold a CDL permit (obtained by passing the written test) for at least seven days before you can take the skills tests, though some states require 14 days or longer.

The written test covers traffic laws, vehicle operation, cargo handling, and safety procedures specific to commercial driving. The pre-trip inspection test requires you to walk around the vehicle and identify working and broken components — mirrors, lights, brakes, tires, and more. The behind-the-wheel test happens on public roads or a closed course and includes basic vehicle control, backing up, and real-world driving scenarios.

You take the written test at your state's Department of Motor Vehicles (DMV) or equivalent agency. The skills tests are usually administered by a third-party tester approved by your state, though some states run their own testing. You will need to bring a commercial vehicle to the skills test — either your own or one provided by a truck driving school.

Medical certification and other requirements

Before you can receive a Class A or Class B license, you must pass a medical examination by a certified medical examiner. This exam checks your vision, hearing, blood pressure, and overall health to may support you are physically capable of operating a large vehicle safely. The medical certificate is valid for two years, and you must renew it before it expires or your CDL becomes invalid.

You must also hold a valid regular driver's license (Class D or equivalent in your state) before you can obtain a CDL. If your regular license is suspended or revoked, your CDL is automatically suspended as well. Some states also require a background check or fingerprinting before issuing a CDL.

Endorsements and restrictions that explore

Certain endorsements add to what you can drive with either Class A or Class B. A Hazmat endorsement lets you transport hazardous materials. A Passenger endorsement is required to drive a bus with more than 15 passengers. A Tanker endorsement is needed for vehicles carrying liquids in bulk. A Doubles/Triples endorsement is required for Class B drivers who want to pull trailers (Class A drivers can pull doubles and triples without this endorsement in most states).

You may also have restrictions placed on your license. A mechanical restriction means you can only drive an automatic transmission vehicle. An intrastate restriction means you can only drive within your state, not across state lines. These restrictions are noted on your license and must be followed.

How long the process takes from start to finish

The entire process from getting your permit to holding your CDL typically takes four to eight weeks, depending on how quickly you study, schedule your tests, and find a vehicle for the skills test. The written test can be taken within days of deciding to pursue the license. The mandatory waiting period between your permit and skills tests adds one to two weeks. Scheduling the skills test itself may take another week or two depending on tester availability in your area.

If you attend a truck driving school, the timeline may be compressed — many schools offer intensive programs that take two to four weeks and include classroom instruction, behind-the-wheel training, and testing coordination. However, you still must satisfy your state's minimum waiting period between permit and skills test.

Frequently Asked Questions

Can I get a Class A or Class B license if I have had traffic violations?

Traffic violations do not automatically disqualify you, but serious violations like DUI, reckless driving, or multiple speeding tickets may prevent you from obtaining a CDL or cause delays. Each state has different rules about what violations are disqualifying. Contact your state's DMV to learn whether your specific violations affect your may be able to access.

Do I need to attend truck driving school to get a Class A license?

No, truck driving school is not required by law. You can study on your own, take the written test at the DMV, and arrange your own vehicle for the skills test. However, many people find school helpful because instructors provide hands-on training and can help you understand the material faster. School also handles scheduling and testing logistics for you.

What happens if I fail one of the three tests?

If you fail the written test, you can retake it after a waiting period (usually a few days to a week, depending on your state). If you fail a skills test, you must wait before retesting, and you may need to pay the testing fee again. There is no limit to how many times you can retake the tests, but each attempt costs money and time.

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

No. Driving a vehicle that requires a Class A license while holding only a Class B license is illegal and can result in fines, license suspension, and criminal charges. You must hold the correct class of license for the vehicle you are operating.

How often do I need to renew my Class A or Class B license?

CDLs are typically valid for four or eight years, depending on your state. You must renew before expiration, and renewal requires passing the written test again and obtaining a new medical certificate. Some states allow you to renew by mail or online if you have no violations, while others require an in-person visit.