What Class A and Class B licenses are, and which one you need

A Class A Commercial Driver's License (CDL) lets you operate 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 26,001 pounds or more where the towed unit weighs more than 10,000 pounds. A Class B CDL covers single vehicles weighing 26,001 pounds or more (but not towing a unit over 10,000 pounds), plus most buses and straight trucks. The difference matters because Class A is the broadest commercial license; Class B is narrower and covers fewer vehicle types.

Which one you need depends on what you will actually drive. If you will haul a loaded trailer behind a tractor unit, you need Class A. If you will drive a dump truck, cement mixer, or city bus, Class B is usually sufficient. If you will drive smaller commercial vehicles — delivery vans, box trucks under 26,001 pounds — you do not need a CDL at all; your regular driver's license covers those. The state DMV can tell you the GVWR of any specific vehicle, and that number determines which license class applies.

Key Takeaways

  • Class A CDL covers tractor-trailers and any combination of vehicles totaling 26,001 pounds or more where the trailer weighs over 10,000 pounds; Class B covers single heavy vehicles and buses but not towing heavy trailers.
  • You must pass a written knowledge test, a pre-trip vehicle inspection test, and a behind-the-wheel driving test specific to the class you are seeking.
  • Most states require you to hold a regular driver's license for at least one year and maintain a clean driving record before you can take a CDL test.
  • Medical certification through a Department of Transportation (DOT) physical is required before you can be issued a CDL, and you must renew it every two years.
  • Endorsements (such as Hazmat, Tanker, or Passenger) add to your base CDL and require separate tests; not all endorsements are available with all license classes.

Age requirements and holding a regular license first

You must be at least 18 years old to hold a Class A or Class B CDL in most states, though some states allow 18-year-olds to drive only intrastate (within state lines). If you want to drive interstate (across state lines), you must be at least 21 years old in all states. This is a federal rule, not a state variation.

Before you can take a CDL test, you must already hold a valid regular driver's license (Class D or equivalent in your state). Most states require you to have held that license for at least one year with no major violations. Some states waive the one-year waiting period if you have held a license in another state for that time. Check your state DMV website for the exact requirement, because it varies.

Your regular license must remain valid throughout the CDL process. If your regular license expires or is suspended, your CDL process will be denied or your CDL will be suspended. This is a common mistake: people focus on the CDL test and forget to renew their underlying regular license.

Medical certification and the DOT physical

Before you can be issued a CDL, you must pass a Department of Transportation (DOT) medical examination performed by a certified medical examiner. This is not optional and not something you can skip. The examiner checks your vision, hearing, blood pressure, ability to control your limbs, and medical history. You will be asked about diabetes, heart conditions, sleep apnea, and medications that affect alertness.

The DOT physical costs between $75 and $200 depending on the provider and your state. You pay out of pocket; there is no government reimbursement. Find an examiner on the National Registry of Certified Medical Examiners at fmcsa.dot.gov. Do not use a regular doctor or urgent care clinic — they are not certified for DOT exams and their results will not be accepted.

Once you pass, you receive a Medical Certificate (Form MCSA-5875) valid for two years. You must carry this certificate with you whenever you drive a commercial vehicle. When it expires, you must take another DOT physical and obtain a new certificate. Many CDL holders forget this renewal and lose their right to drive commercially until they complete a new exam.

The three-part CDL test: knowledge, pre-trip inspection, and driving

The CDL test has three separate components, and you must pass all three to be issued a license. You can usually take them on the same day or spread them across multiple visits, depending on your state's DMV rules.

The written knowledge test covers federal and state commercial driving rules, vehicle safety, hazard recognition, and brake systems. The test is typically 50 questions, and you must score at least 80 percent to pass. You can study using your state's CDL manual (free from the DMV website) or commercial study guides. Most people spend 20 to 40 hours studying before taking this test. You take this test at a DMV office on a computer or paper form.

The pre-trip vehicle inspection test requires you to walk around and inspect a real commercial vehicle — checking tires, lights, mirrors, brakes, coupling devices, and safety equipment — while an examiner watches and listens. You must identify defects and explain what you are checking and why. This test has no passing score; the examiner straightforward notes whether you performed a thorough, safe inspection. Many people fail this test because they rush or forget to check specific components. You take this test at a DMV testing site with an actual vehicle present.

The behind-the-wheel driving test lasts 30 to 45 minutes. You drive a commercial vehicle of the class you are seeking (Class A tractor-trailer or Class B straight truck) while an examiner sits beside you. You will be asked to perform specific maneuvers — backing, lane changes, turns, emergency stops — and to drive on city streets and highways. The examiner scores you on vehicle control, safety awareness, and rule compliance. This is the test most people find most stressful because it is live and when ready.

Endorsements: Hazmat, Tanker, Passenger, and others

A CDL endorsement is an additional qualification that allows you to haul specific cargo or operate specific vehicle types. You cannot haul hazardous materials, operate a tanker truck, or drive a bus carrying passengers without the correct endorsement, even if you hold a valid CDL. Endorsements are not automatic; you must take a separate written test for each one.

Common endorsements include Hazmat (H) for hazardous materials, Tanker (T) for tank vehicles, Passenger (P) for buses, and Double/Triple Trailers (N) for pulling multiple trailers. Some endorsements are available only with Class A (for example, you cannot get a Double/Triple endorsement with Class B). Your state DMV website lists which endorsements are available and which classes they attach to.

To obtain an endorsement, you take a written test specific to that endorsement at a DMV office. For Hazmat, you must also pass a federal background check and pay a fee (typically $85 to $100). The Hazmat endorsement is valid for five years; most other endorsements are valid for the life of your CDL (though they expire when your CDL expires). Plan to spend 10 to 20 hours studying for each endorsement test.

Fees, timelines, and state-by-state variation

CDL fees vary significantly by state. A Class A or Class B CDL typically costs between $50 and $200 for the license itself, plus test fees (usually $10 to $50 per test component). Add the DOT physical ($75 to $200), study materials, and any endorsement tests, and your total out-of-pocket cost ranges from $300 to $600 before you are licensed. Some states charge more; some charge less. Check your state DMV website for exact fees.

The timeline from start to finish depends on how quickly you study and how soon you can schedule tests. If you already hold a regular license and have your DOT medical certificate, you can take all three CDL tests in one day at many DMV offices. However, most people spend 4 to 12 weeks studying before they feel ready. If you need to obtain your regular license first, add another 1 to 4 weeks for that process.

Some states allow you to take the knowledge test online from home; others require you to come to a DMV office. Some states let you schedule all three tests at once; others require you to pass the knowledge test before you can book the pre-trip and driving tests. A few states have longer waiting periods between tests. Your state DMV website will specify the exact rules and whether you can book tests online or must call or visit in person.

Common reasons CDL applications are denied or delayed

The most frequent reason for denial is a failed medical examination. If you have uncontrolled high blood pressure, uncorrected vision problems, or a medical condition the DOT considers disqualifying, you will not be issued a CDL until that condition is treated or resolved. Some conditions (like certain seizure disorders or severe sleep apnea) may permanently disqualify you; others (like high blood pressure) can be managed with medication and a follow-up exam.

The second most common reason is a suspended or revoked regular driver's license. If your Class D license has been suspended for any reason — unpaid tickets, DUI, points accumulation — your CDL will not be issued. You must clear the suspension on your regular license first. Similarly, if you have been convicted of certain crimes (felonies involving drugs or violence, for example), you may be permanently barred from holding a CDL regardless of your driving record.

Test failures also delay the process. If you fail the written knowledge test, you can usually retake it after a waiting period (typically 7 days). If you fail the pre-trip or driving test, the waiting period is often 14 days. Some states allow unlimited retakes; others cap the number of attempts. Failing all three tests multiple times can take months to resolve.

Frequently Asked Questions

Can I get a Class A CDL if I have had a DUI in the past?

A single DUI does not automatically disqualify you, but it will be scrutinized. Most states allow you to obtain a CDL if the DUI is more than 5 to 10 years old and you have a clean record since then. However, if you have multiple DUIs, a DUI while driving commercially, or a DUI within the last few years, you will likely be denied. Contact your state DMV to ask about your specific situation.

Do I need a Class A or Class B if I drive for a delivery company?

It depends on the vehicle weight. Most delivery vans and box trucks weigh under 26,001 pounds, so you do not need a CDL at all — your regular license is sufficient. If your employer uses vehicles over 26,001 pounds, you will need either Class A or Class B depending on whether you tow a trailer. Ask your employer for the GVWR of the vehicle you will drive; that number determines which license you need.

What happens if my DOT medical certificate expires while I am driving?

Your CDL becomes invalid when ready. You cannot legally drive a commercial vehicle. You must obtain a new DOT physical and medical certificate before you can drive again. Many employers will suspend you from work until you renew. Set a calendar reminder six months before your certificate expires so you have time to schedule and complete the exam.

Can I take the CDL tests in a language other than English?

Most states offer the written knowledge test in Spanish and sometimes other languages, but the pre-trip inspection and driving tests are conducted in English because you must communicate with the examiner. If English is not your first language, consider hiring a professional CDL instructor who can teach you both the material and the English terminology you will need during testing.

How long does a Class A or Class B CDL last once I have it?

A CDL is typically valid for eight years from the date of issue, though some states issue them for four or five years. You must renew before it expires by visiting your state DMV, paying a renewal fee (usually $50 to $150), and passing a new DOT medical examination. You do not need to retake the knowledge, pre-trip, or driving tests to renew — only the medical exam.