What you need to do to get a commercial driver's license

A commercial driver's license (CDL) is a separate credential from a regular driver's license, issued by your state's Department of Motor Vehicles or equivalent agency. You cannot straightforward upgrade an existing license — you must pass a written knowledge test, a skills test behind the wheel, and a medical examination. The process takes weeks to months depending on your state and how quickly you schedule tests, and costs vary from around $100 to $300 in total fees, though some states charge more.

You start by meeting your state's baseline requirements, which almost always include being at least 18 years old (21 if you want to drive across state lines), holding a valid regular driver's license, and passing a Department of Transportation medical exam. After that, you study for and pass the written test covering the rules specific to large vehicles, then schedule and pass the practical driving test with an examiner in an actual commercial truck or bus. The order and exact rules vary slightly by state, so you will need to check your state's DMV website for the specific sequence and fees.

Key Takeaways

  • You must be at least 18 years old and hold a valid regular driver's license before you can begin the CDL process in any state.
  • A Department of Transportation medical exam is required and must be passed before you take the written test; the exam checks vision, hearing, blood pressure, and other health factors that affect safe driving of large vehicles.
  • The written test covers vehicle inspection, safe driving practices, and rules specific to the class of vehicle you want to drive, and you study from your state's CDL manual.
  • The practical driving test happens in an actual commercial vehicle and includes a pre-trip inspection, basic vehicle control, and an on-road driving portion.
  • Different classes of CDL (Class A, B, and C) allow you to drive different vehicle types and weights, and your state determines which class you need for your intended job.

Understanding CDL classes and what each one allows

States issue three classes of commercial driver's licenses, and the class you need depends on the vehicle's gross vehicle weight rating (GVWR) and what you will be hauling. Class A covers the heaviest vehicles — tractor-trailers and any combination of vehicles totaling 26,001 pounds or more — and is what most long-haul truck drivers hold. Class B covers single vehicles weighing 26,001 pounds or more but not tractor-trailers, such as large buses or dump trucks. Class C covers smaller commercial vehicles and is less common; it is typically for drivers of vehicles carrying 16 or more passengers or hazardous materials in smaller quantities.

Your employer or the job you are training for will usually tell you which class you need. If you are unsure, your state's DMV website lists the exact weight and vehicle-type thresholds for each class. You take the written and practical tests for the specific class you are pursuing, and you cannot use a Class B license to drive a Class A vehicle, even if you have passed the Class B test.

Medical examination and what disqualifies you

Before you sit for the written test, you must pass a Department of Transportation (DOT) medical examination conducted by a certified medical examiner. This is not your regular doctor's checkup — it is a specific evaluation that checks your vision (you need at least 20/40 in each eye, corrected or uncorrected), hearing, blood pressure, and ability to operate a large vehicle safely. The examiner also reviews your medical history for conditions like epilepsy, diabetes (depending on how it is managed), heart disease, or sleep apnea that could affect your ability to drive safely.

Some conditions do not automatically disqualify you but require additional documentation or monitoring. For example, if you take insulin for diabetes, you may still be able to get a CDL if your condition is well-controlled and you have a letter from your doctor. If the examiner finds a disqualifying condition, you will not receive the medical certificate needed to proceed, and you cannot take the written or practical test without it. You can reapply after the condition is treated or resolved, or you can seek a second opinion from another certified examiner if you disagree with the result.

The written knowledge test and how to prepare

The written test is administered by your state's DMV and covers the rules and safe practices specific to commercial driving. The test typically has 50 questions covering topics like vehicle inspection (how to check brakes, lights, and tire condition before driving), safe driving practices (speed, following distance, backing up), and regulations (hours of service, weight limits, hazmat rules if applicable). You usually need to score at least 80 percent to pass, though some states require higher scores.

Your state's DMV publishes a free CDL manual that covers all the material on the test — this is your primary study resource. Many people also use third-party study guides, videos, and practice tests available online, though these are optional. Most people spend two to four weeks studying before taking the test, depending on their background and how much time they can dedicate. You can take the test as many times as you need to pass, though some states charge a fee each time you retake it.

The practical driving test and what the examiner evaluates

Once you pass the written test, you schedule the practical driving test with your state's DMV or an approved third-party testing facility. The test happens in an actual commercial vehicle — usually a truck or bus provided by a training school or employer — and takes two to three hours. The examiner evaluates three main sections: the pre-trip inspection (you walk around the vehicle and point out safety features and check for damage), basic vehicle control (you perform maneuvers like backing up and parking in a confined space), and on-road driving (you drive on public roads while the examiner observes your speed, lane control, braking, and decision-making).

You must pass all three sections to pass the test overall. If you fail one section, you typically must retake the entire test, though some states allow you to retake only the failed section. The examiner is looking for safe driving habits and knowledge of the vehicle's capabilities — not perfection. Minor mistakes do not automatically fail you, but unsafe actions like rolling through a stop sign or failing to check your mirrors will. Most people who have trained with a CDL school or spent time practicing with an experienced driver pass on their first or second attempt.

Endorsements and restrictions based on what you will haul

Beyond the basic CDL class, your license may include endorsements that allow you to haul specific cargo or operate certain vehicle types. The most common endorsement is Hazmat (H), required if you will transport hazardous materials like fuel or chemicals. Other endorsements include Tanker (N) for vehicles carrying liquids in bulk, Passenger (P) for buses carrying more than 15 people, and Double/Triple Trailers (T) for pulling multiple trailers. Each endorsement requires passing an additional written test on top of the base CDL test.

Your license may also carry restrictions that limit where or how you can drive. For example, if you wear corrective lenses, your license will note that you must wear them while driving. If you are under 21, your license may restrict you to intrastate driving (within your state only) rather than interstate. These restrictions are printed on your license and are legally binding — driving outside your restrictions can result in fines or loss of your license.

Timeline and costs: what to budget and how long it takes

The entire process from starting to study to holding your CDL typically takes two to four months, though it can be faster or slower depending on how quickly you schedule tests and how many attempts you need. The medical exam usually happens first and takes one appointment. The written test can be scheduled within days or weeks depending on your state's DMV availability. The practical test often has a longer wait — some states have backlogs of several weeks — so you may want to schedule it as soon as you pass the written test.

Total costs vary by state but generally fall between $100 and $300 for DMV fees (written test, practical test, and license issuance). The medical exam costs $50 to $150 depending on the examiner. If you attend a CDL training school, that is a separate cost ranging from $3,000 to $7,000 depending on the school and program length, though many employers cover this cost for new hires. If you are training on your own or with an employer, you only pay the DMV and medical exam fees.

Frequently Asked Questions

Can I get a CDL if I have a DUI or other traffic violations on my record?

A DUI does not automatically disqualify you, but it will be reviewed during your process. Some states have waiting periods or require you to demonstrate a clean driving record for a certain number of years after the violation. Contact your state's DMV to learn the specific rules, as they vary significantly by state and the severity of the violation.

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

You can study on your own using your state's free CDL manual and take the tests without attending a formal school. However, you will need access to a commercial vehicle for the practical test, which most people do not own. Many employers provide training or partner with schools, and some people arrange practice time with experienced drivers they know.

What happens if I fail the practical driving test?

You can retake the test, usually after waiting a few days to a week. There is typically a fee each time you retake it. Most states allow unlimited retakes, though some cap the number of attempts per year. Taking a few practice sessions with a trainer or experienced driver between attempts significantly improves your chances of passing the second time.

Can I drive a commercial vehicle with a regular driver's license while I am studying for my CDL?

No. Driving a commercial vehicle without a valid CDL is illegal and can result in fines and criminal charges. You must hold the CDL before you operate a commercial vehicle on public roads, even if you are in training or have already passed the written test.

How long is a CDL valid, and do I need to renew it?

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