The difference between Class A and Class B licenses

A Class A commercial driver's license (CDL) lets you drive the largest trucks on the road — typically vehicles with a gross vehicle weight rating (GVWR) of 26,001 pounds or more, or any combination of vehicles totaling that weight or more. A Class B CDL covers single vehicles weighing 26,001 pounds or more that are not tractor-trailers, plus lighter vehicles if you're transporting certain cargo. The main difference is that Class A covers tractor-trailers and doubles; Class B does not.

Both require a commercial driver's license rather than a standard driver's license. Both demand a written knowledge test, a skills test, and a medical certificate. The Class A test is harder because the vehicles are larger and the combinations more complex. If you pass the Class A test, you can legally drive Class B vehicles, but not the reverse.

Your state's Department of Motor Vehicles (DMV) or equivalent agency issues both. The specific rules about what each class covers vary slightly by state, so checking your state's CDL handbook before you test is essential.

Key Takeaways

  • Class A CDLs cover tractor-trailers and double trailers; Class B CDLs cover single heavy vehicles but not tractor-trailers.
  • Both require passing a written test, a behind-the-wheel skills test, and a medical examination before you can be issued the license.
  • A Class A license allows you to drive Class B vehicles, but a Class B license does not allow you to drive Class A vehicles.
  • Your state's CDL handbook defines the exact weight thresholds and vehicle types for each class in your jurisdiction.

What vehicles you can drive with a Class A license

With a Class A CDL, you can drive tractor-trailers (also called semi-trucks or 18-wheelers), doubles, and triples. You can also drive any Class B or Class C vehicle. This is the broadest commercial license available, which is why it requires the most rigorous testing.

Class A is the standard license for long-haul trucking, local delivery of heavy goods, and any job that involves pulling trailers. If your job description says "truck driver" without qualification, it usually means Class A.

You can also drive smaller vehicles under a Class A license — a pickup truck, a van, or a car — as long as you're not transporting hazardous materials or passengers for hire in a way that requires additional endorsements.

What vehicles you can drive with a Class B license

With a Class B CDL, you can drive single vehicles weighing 26,001 pounds or more that are not part of a tractor-trailer combination. This includes straight trucks (box trucks, dump trucks, cement mixers), large buses, and some RVs. You can also drive any Class C vehicle.

Class B is common for local delivery, waste management, construction, and public transit. If you're driving a large box truck for a moving company or a dump truck for a construction site, you likely need a Class B license.

You cannot drive a tractor-trailer or pull a trailer with a Class B license, even if the trailer is light. The restriction is about the combination, not just the weight.

Endorsements and restrictions that explore to both classes

Both Class A and Class B licenses can carry endorsements — additional qualifications that let you transport specific cargo or passengers. The most common endorsement is H (hazmat), which allows you to transport hazardous materials. Others include P (passenger) for buses, T (double/triple trailers) for Class A drivers, and N (tank vehicles) for transporting liquids in bulk.

Both licenses can also carry restrictions. A restriction L means you cannot drive air-braked vehicles. A restriction Z means you cannot drive manual transmission vehicles. Your state assigns restrictions based on your skills test performance or medical history.

If you need an endorsement, you take an additional written test specific to that endorsement. Hazmat endorsements also require a federal background check and fingerprinting.

The testing process for Class A and Class B

Both licenses require three steps: a written knowledge test, a skills test, and a medical examination. The written test covers vehicle operation, safety, and road rules specific to commercial driving. The skills test happens in the vehicle you'll be tested in and includes a pre-trip inspection, a basic control test, and a road test.

The Class A test is generally considered harder because tractor-trailers are longer, have more blind spots, and require different braking and turning techniques than straight trucks. The road test for Class A often includes backing up with a trailer, which is a major source of test failures.

The medical examination is the same for both classes. A certified medical examiner checks your vision, hearing, blood pressure, and other factors. You must pass to receive a medical certificate, which is valid for two years (or one year if you're over 65).

Most states require you to hold a regular driver's license first and to pass a written CDL permit test before you can schedule the skills test. Some states let you study with a CDL permit for 14 days; others require longer. Check your state's rules before you start.

When you need a Class A versus a Class B license

You need a Class A license if your job involves pulling a trailer of any kind — a flatbed, a refrigerated trailer, a tanker, a car hauler, or a double trailer. You also need it if you're driving a tractor-trailer combination, even if the trailer is empty.

You need a Class B license if you're driving a single heavy vehicle — a dump truck, a concrete mixer, a large box truck, or a bus — but not pulling anything behind it. Local delivery drivers, waste collection operators, and construction equipment operators typically hold Class B licenses.

If you're unsure whether your job requires a commercial license at all, the rule is straightforward: if the vehicle's GVWR is 26,001 pounds or more, you need a CDL. Your employer should tell you which class they need you to hold.

How to get your free guide with CDL testing in your state

Contact your state's DMV or the equivalent agency (some states call it the Department of Transportation or the Secretary of State). Ask for the CDL handbook and the process form. The handbook explains the written test content, the skills test requirements, and the medical standards for your state.

Schedule a medical examination with a certified medical examiner. You cannot take the written test without proof of a valid medical certificate. The exam costs money — usually $50 to $150 — and is not covered by the state.

Study the handbook, take the written test at your DMV, and if you pass, you'll receive a CDL permit. Then schedule your skills test. Many states require you to wait a certain number of days between the permit and the skills test; others let you test when ready. Bring the vehicle you'll be tested in to the skills test appointment.

Frequently Asked Questions

Can I get a Class A license if I've never driven a truck before?

Yes, but most people take a commercial driving school course first. The course teaches you how to operate the vehicle, pass the skills test, and meet safety standards. Some employers offer paid training; others require you to complete training on your own before hiring. Check with your employer or a local CDL school about costs and timing.

What happens if I fail the skills test?

You can retake it. Most states let you schedule another test within a few days or weeks. You keep your CDL permit and can test again. There is usually a fee for each test attempt. Some people fail once or twice before passing; it's not unusual.

Do I need a Class A or Class B license to drive my own RV?

It depends on the RV's GVWR. If it's 26,001 pounds or more, you need a Class B CDL. If it's under that, you can drive it with a regular driver's license. Check your RV's registration or manual for the GVWR. Some large motorhomes require a Class B license.

Can I switch from Class B to Class A after I already have my Class B license?

Yes. You take the Class A written test and skills test. You don't need to retake the medical exam if your medical certificate is still valid. Some states let you upgrade without retesting the written portion if you've held your Class B for a certain time, but this varies — ask your DMV.

How long is a CDL valid?

A CDL is valid for eight years in most states, though some states issue them for shorter periods. Your medical certificate must be renewed every two years (or every year if you're over 65). If your medical certificate expires, your CDL is no longer valid for commercial driving, even though the license itself hasn't expired.