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) above 26,001 pounds. A Class B license lets you drive medium-sized commercial vehicles, usually those between 10,001 and 26,000 pounds GVWR. The main dividing line is weight: Class A covers the heaviest rigs, while Class B covers the next tier down.

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 have to take the full CDL test for whichever class you need. The class you hold determines what you are legally allowed to drive for work.

If you drive a vehicle that falls between these weights, or if you are unsure whether your job requires a CDL at all, your state's Department of Motor Vehicles (DMV) can tell you which class applies to your situation. Some states also have Class C licenses for smaller commercial vehicles, though rules vary by state.

Key Takeaways

  • Class A licenses cover the heaviest commercial trucks (over 26,001 pounds GVWR), while Class B covers medium trucks (10,001 to 26,000 pounds GVWR).
  • Both require passing a written test, a skills test, and a medical exam — you cannot straightforward upgrade from one class to another.
  • Your job determines which class you need; driving a vehicle heavier than your license allows is illegal and can result in fines and job loss.
  • Most states require you to hold a regular driver's license first, and you must be at least 18 years old (21 in some states for interstate driving).
  • Training programs and study materials are available through your state's DMV, driving schools, and trucking companies that hire new drivers.

What vehicles fall under each class

Class A covers tractor-trailers, semi-trucks, and any combination vehicle where the towed unit weighs more than 10,000 pounds. This includes long-haul trucks, dump trucks pulling trailers, and tanker trucks. If you see an 18-wheeler on the highway, the driver holds a Class A license.

Class B covers straight trucks — single vehicles without a trailer — that weigh between 10,001 and 26,000 pounds. This includes delivery trucks, garbage trucks, cement mixers, and school buses. The vehicle itself is the heavy part; nothing is being towed behind it.

The weight that matters is the gross vehicle weight rating (GVWR), not what the truck actually weighs on any given day. The GVWR is printed on the truck's door frame or in the owner's manual and tells you the maximum weight the vehicle is designed to carry. If a truck's GVWR is 26,001 pounds or higher, you need a Class A license to drive it legally, even if it is empty.

Testing and training requirements

To get a Class A or Class B license, you must pass three separate tests: a written knowledge test, a pre-trip inspection test, and a behind-the-wheel driving test. Each test covers different material, and you typically cannot take them all on the same day.

The written test covers traffic laws, safe driving practices, and rules specific to commercial vehicles. You study from your state's CDL manual, which your DMV provides free. Many states allow you to take this test at a DMV office or at an approved testing center.

The pre-trip inspection test requires you to walk around the vehicle and point out safety features and potential problems — things like tire condition, brake function, and lighting. You do not actually drive during this test; you explain what you are checking and why.

The behind-the-wheel test is a 30- to 45-minute drive with an examiner in the truck. You perform specific maneuvers like backing up, parking, and lane changes, and you drive on public roads. This is the test most people find hardest because it combines real-world driving with the pressure of being evaluated.

Medical certification and age requirements

Before you can take any CDL test, you must pass a medical exam performed by a certified medical examiner — not your regular doctor. The examiner checks your vision, hearing, blood pressure, and overall fitness to drive. You receive a Medical Certificate (also called a medical card) that you carry with your license.

Most states require you to be at least 18 years old to get a Class A or B license for intrastate driving (driving within your state). If you want to drive across state lines, many states require you to be 21. Some states have different age rules, so check with your state's DMV.

You must also hold a valid regular driver's license before you can get a CDL. Some states require you to hold it for a certain amount of time, though most do not. Your regular license and CDL are separate documents.

How to prepare for the CDL test

Start by getting your state's official CDL manual from your DMV website or office. Read it cover to cover — it contains everything the written test covers, and it is free. Many people read it twice: once to learn the material, and once to review before the test.

Take practice tests online. Your state's DMV website often has sample questions, and many third-party websites offer free practice tests that mirror the real exam. These help you identify weak areas before test day.

For the pre-trip inspection and behind-the-wheel tests, hands-on practice is essential. Some trucking companies offer free training to people they plan to hire, which covers both the written material and vehicle operation. Driving schools that specialize in CDL training are also available in most areas, though they charge a fee (typically $1,000 to $5,000 depending on the program length).

If you are training through a trucking company, they often provide study materials and may even pay for your medical exam. Ask potential employers whether they offer training or reimbursement — many do, especially if you commit to working for them for a set period after you pass.

Endorsements and restrictions

Beyond Class A and B, you may need additional endorsements on your license depending on what you carry or tow. A Hazmat endorsement is required if you transport hazardous materials. A Tanker endorsement is required for tanker trucks. A Passenger endorsement is required if you drive a bus or van carrying 16 or more people.

Each endorsement requires passing an additional written test. You can add endorsements to your license after you pass your base CDL test, or you can take them at the same time if you are ready.

Some licenses also carry restrictions — limitations on what you can drive. For example, if you fail the air brake portion of the test, you may receive a restriction that prevents you from driving vehicles with air brakes. You can remove restrictions by retesting that specific component.

Maintaining your license and staying current

Your medical certificate expires every two years (or every year if you are over 65). You must renew it before it expires, or your CDL becomes invalid even if the license itself has not expired. Mark your calendar when you get your medical exam so you do not miss the renewal date.

Your CDL itself renews on a schedule set by your state — typically every four to eight years. Renewal requirements vary; some states require you to retake the written test, while others allow you to renew by mail or online.

Certain traffic violations can result in losing your CDL, even if you hold a regular license. Speeding, reckless driving, and driving under the influence carry harsher penalties for CDL holders. A single serious violation can disqualify you from commercial driving for a set period.

Frequently Asked Questions

Can I get a Class B license if I only need to drive small trucks?

Yes. If your vehicle's GVWR is 26,000 pounds or less, you need a Class B license at most. If it is under 10,001 pounds, you may not need a CDL at all — check your state's rules. Your employer or the vehicle's documentation will tell you what is required.

Do I need a CDL to drive a personal truck?

Only if you use it for work. If you own a heavy truck but drive it only for personal use, you do not need a CDL. The moment you use it to haul cargo or passengers for money, you need the appropriate license. Some states have exceptions for farmers or certain other uses — ask your DMV.

How long does it take to get a CDL?

The written test can be passed in one or two visits to the DMV. The pre-trip and driving tests usually happen on separate days. If you study on your own, the whole process takes a few weeks. Formal training programs typically take four to eight weeks of full-time study.

What happens if I drive without the right class of license?

You face fines, points on your driving record, and possible jail time depending on your state. Your employer could also fire you, and your insurance may not cover an accident if you were driving illegally. It is not worth the risk.

Can I switch from Class B to Class A?

You have to take the full Class A test — you cannot straightforward upgrade. However, some of what you learned for Class B applies to Class A, so studying may be faster the second time. You must pass all three tests again.