The basic requirements for a CDL

To get a Commercial Driver's License (CDL), you must be at least 18 years old (21 if you want to drive across state lines or haul hazardous materials), hold a valid regular driver's license, and pass a medical examination by a certified medical examiner. You will also need to pass a written knowledge test specific to the class of vehicle you want to drive, a pre-trip vehicle inspection test, and a behind-the-wheel driving test with an examiner.

The written test covers federal motor carrier safety regulations, vehicle operation, and safe driving practices. The inspection test requires you to walk around and check critical parts of a truck or bus — brakes, lights, tires, mirrors, coupling devices — and explain what you are looking for. The driving test happens on public roads or a closed course and lasts 30 to 45 minutes.

You must also obtain a Medical Certificate from a FMCSA-certified medical examiner (not your regular doctor). This certificate confirms you meet vision, hearing, and general health standards set by the Federal Motor Carrier Safety Administration. The certificate is valid for two years and must be renewed before it expires.

Key Takeaways

  • You must be at least 18 years old, hold a valid regular driver's license, and pass a medical exam by an FMCSA-certified examiner before you can test for a CDL.
  • The CDL process involves three separate tests: a written knowledge test, a vehicle inspection test, and a behind-the-wheel driving test administered by your state's licensing agency.
  • Different CDL classes (A, B, and C) require you to drive different vehicle types during the road test, so you must know which class matches the work you plan to do.
  • You will need to provide proof of citizenship or legal residency, a Social Security number, and a valid form of identification when you explore at your state's DMV or licensing office.
  • Some states require you to hold a Commercial Learner's Permit (CLP) for a set period before you can take the road test, which involves passing the written test first.

Medical certification and the FMCSA exam

The medical exam is not optional and not something your personal physician can perform. You must see a FMCSA-certified medical examiner listed on the National Registry of Certified Medical Examiners, which you can search on the FMCSA website. The examiner checks your vision (at least 20/40 in each eye, corrected or uncorrected), hearing, blood pressure, and general health history.

You will be asked about medications, sleep disorders, diabetes, heart conditions, and other health issues that could affect safe driving. Be honest — lying on the medical form is a federal offense. If you have a condition that might disqualify you, the examiner can sometimes issue a certificate with restrictions (such as daylight driving only or automatic transmission only) rather than denying you outright.

The Medical Certificate itself is a small document you carry with your CDL. It expires after two years, and you must renew it before it lapses. Some states allow you to renew by mail or online if nothing has changed in your health; others require an in-person visit.

The written knowledge test and what it covers

The written test is administered by your state's DMV or licensing office and covers the Commercial Driver's Manual, which your state publishes. The test typically has 50 questions, and you must score at least 80 percent to pass. You can usually take it on a computer at the DMV office.

The test covers federal regulations on hours of service (how long you can drive before resting), vehicle maintenance, cargo securement, brake systems, and how to handle emergencies like brake failure or a jackknife. It also covers traffic laws specific to commercial vehicles — for instance, the rules for passing, backing up, and parking a large truck.

If you are testing for a CDL with hazardous materials endorsement, you will take an additional written test on hazmat regulations. If you are testing for a passenger endorsement (to drive a bus or van), there is a separate test on passenger safety and loading procedures.

The vehicle inspection test and pre-trip walkthrough

The pre-trip inspection test requires you to demonstrate that you know how to check a commercial vehicle before you drive it. You will be given a vehicle — usually a tractor-trailer, straight truck, or bus depending on the CDL class you are testing for — and asked to perform a pre-trip inspection. You have about 15 minutes to walk around the vehicle, point out key components, and explain what you are checking and why.

The examiner is looking for your knowledge, not perfection. You do not have to find every problem, but you should be able to identify the major systems: air brakes, hydraulic brakes, lights, wipers, mirrors, tires, coupling devices (if applicable), and emergency equipment. You should explain what you are looking for — for example, "I am checking the tread depth on the tires to make sure it meets the minimum of 4/32 of an inch."

Common reasons people fail this test are forgetting to check both sides of the vehicle, not knowing the names of parts, or failing to explain what they are looking for. Studying the pre-trip inspection section of your state's Commercial Driver's Manual and practicing on an actual vehicle before test day will help you pass.

The behind-the-wheel driving test

The road test is the final and most difficult part of the CDL process. You will drive a commercial vehicle on public roads or a closed course for 30 to 45 minutes while an examiner watches and scores your performance. The examiner is assessing your ability to control the vehicle, follow traffic laws, make safe decisions, and handle the size and weight of a commercial truck or bus.

You will be asked to perform specific maneuvers: backing up in a straight line, backing into a dock or alley, parking between two vehicles, and performing a lane change. You will also drive on highways, through intersections, and possibly through residential areas. The examiner will ask you to demonstrate skills like smooth acceleration, proper braking, correct mirror checking, and safe turning.

You must bring your Medical Certificate and proof of vehicle insurance to the test. The vehicle must be the same class as the CDL you are testing for — if you are testing for a Class A CDL, you must drive a tractor-trailer combination; for Class B, a straight truck or bus; for Class C, a smaller commercial vehicle. Failing the road test means you can retake it, usually within a few weeks, but you will have to pay the test fee again.

State-by-state differences and the Commercial Learner's Permit

CDL requirements are set by federal law, but each state administers its own tests and issues its own licenses. The written test content is similar across states, but the specific questions and passing score may vary slightly. Some states require you to hold a Commercial Learner's Permit (CLP) for a minimum period — often 14 days — before you can take the road test. During this time, you can drive a commercial vehicle only with a licensed CDL holder in the passenger seat.

To get a CLP, you pass the written knowledge test and the pre-trip inspection test, but not the road test. The CLP is valid for a set period (usually 180 days to one year, depending on your state) and allows you to practice under supervision. Some states waive the CLP requirement if you have military experience driving commercial vehicles.

Check your state's DMV website for the exact requirements in your state, including test fees, required documents, and whether you need to schedule an appointment. Fees typically range from $50 to $200 for the written test and $100 to $300 for the road test, but this varies by state.

Documents you will need to bring

When you explore for a CDL at your state's DMV or licensing office, you will need to provide proof of identity, proof of citizenship or legal residency, and your Social Security number. Acceptable forms of ID include a passport, birth certificate, or state ID. You will also need your current regular driver's license and your Medical Certificate.

Some states require additional documents, such as proof of address (a utility bill or lease) or a completed medical history form. Bring originals or certified copies — photocopies are usually not accepted. If you are explore for a hazmat endorsement, you may need to undergo a background check and provide fingerprints.

Before you go to the DMV, check your state's specific document checklist on its website. Showing up without the right documents will delay your process and may require you to return another day.

Frequently Asked Questions

Can I take the CDL tests if I have a suspended or revoked driver's license?

No. You must have a valid, unrestricted regular driver's license to hold a CDL. If your license is suspended or revoked, you cannot test for or hold a commercial license. You must restore your regular license first.

What happens if I fail the road test?

You can retake the road test after a waiting period set by your state — usually a few days to a week. You will have to pay the test fee again. Most people pass on the second or third attempt after additional practice. Failing does not affect your regular driver's license or your CLP.

Do I need to attend a CDL training school, or can I study on my own?

You are not required to attend a formal school, but many people do because it provides structured instruction and access to practice vehicles. You can study the Commercial Driver's Manual on your own and practice with someone who already has a CDL. Some employers offer CDL training as part of hiring.

How long is a CDL valid once I get it?

A CDL is typically valid for four to eight years, depending on your state. You must renew it before it expires. Renewal usually involves passing a new medical exam and paying a renewal fee, though some states may require you to retake the written test as well.

Can I get a CDL if I have a criminal record?

A criminal record does not automatically disqualify you from a CDL, but certain convictions — especially those involving drugs, alcohol, or violence — may prevent you from being hired by trucking companies or from obtaining a hazmat endorsement. The FMCSA has specific rules about which convictions disqualify you from certain endorsements. Check with your state's licensing office or the FMCSA website for details.