A commercial driver's license (CDL) is a separate credential from a regular driver's license, required by federal law to operate most trucks over a certain weight
If you drive a truck for work, you need a Commercial Driver's License (CDL) issued by your state, not just a standard driver's license. The federal government sets the baseline rules, but each state administers its own CDL program and sets the exact testing procedures, fees, and renewal schedules.
The threshold is straightforward: if you operate a single vehicle 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 10,001 pounds or more, you must hold a CDL. Some states also require a CDL for smaller vehicles used commercially in certain ways — check your state's rules, because they vary.
A CDL is not a commercial endorsement added to your regular license. It replaces your regular driver's license entirely. You cannot hold both at the same time in the same state.
Key Takeaways
- A CDL is required by federal law to operate trucks over 26,001 pounds GVWR, and your state's Department of Motor Vehicles (DMV) or equivalent agency issues it.
- You must pass a written knowledge test, a skills test (pre-trip inspection, basic control, and road test), and a medical examination before you can receive a CDL.
- Most states require you to hold a valid regular driver's license and pass a background check before you can even take the CDL written test.
- CDL classes (Class A, B, and C) determine what you can legally drive, and endorsements (such as hazmat or passenger) add restrictions or permissions on top of your class.
- Renewal periods and fees vary by state, but most CDLs are valid for four or five years and require medical recertification.
The three CDL classes and what each one covers
Your state will issue you one of three classes based on the vehicle you drive and the test you pass. Class A covers the widest range: any combination of vehicles where the towed unit weighs 10,001 pounds or more. This is the most common class for long-haul truckers and is what most people mean when they say "CDL."
Class B covers a single vehicle with a GVWR of 26,001 pounds or more, or any combination where the towed unit weighs 10,000 pounds or less. This covers many delivery trucks, dump trucks, and smaller commercial vehicles.
Class C is the least common and covers vehicles under 26,001 pounds GVWR that require a CDL only because of what they carry — typically vehicles transporting hazardous materials or 16 or more passengers (including the driver). Some states do not issue Class C licenses; they use Class B instead.
You test for the specific class you need. You cannot test for Class A and then downgrade to Class B; you take the test that matches the work you will do.
Written knowledge test requirements and what to study
Before you can take the skills test, you must pass a written knowledge test at your state's DMV or testing location. The test covers the Federal Motor Carrier Safety Regulations (FMCSR), vehicle operation, cargo handling, and safety procedures. The number of questions and passing score vary by state, but most require 80 percent correct.
You will answer questions about air brakes, combination vehicles, hazardous materials (if you are testing for that endorsement), passenger transport (if applicable), and general safe driving practices. Many states provide a study manual free on their DMV website; some offer practice tests online. You can retake the written test if you fail, though most states charge a fee each time.
If you hold certain endorsements — such as hazmat or passenger — you take additional written tests specific to those endorsements. These are separate from the general CDL knowledge test and must be passed before you can take the skills test for that endorsement.
The skills test: pre-trip inspection, basic control, and road test
After passing the written test, you schedule a skills test with an examiner approved by your state. The skills test has three parts, all conducted on the same day in most states.
The pre-trip inspection requires you to walk around the vehicle and identify components, check their condition, and explain what you are looking for. You must demonstrate knowledge of lights, brakes, tires, coupling devices (if applicable), and safety equipment. You do not have to actually repair anything; you have to show you know what to inspect and why.
The basic control portion tests your ability to maneuver the vehicle in a controlled environment — usually a closed course or parking lot. You perform tasks like backing in a straight line, backing into an offset alley, and performing a 90-degree turn. These test your spatial awareness and understanding of the vehicle's dimensions and handling.
The road test
Medical certification and what disqualifies you
Before you receive your CDL, you must pass a medical examination conducted by a Medical Examiner certified by the Federal Motor Carrier Safety Administration (FMCSA). This is not your regular doctor; it must be someone on the FMCSA's National Registry of Certified Medical Examiners. Your state's DMV can direct you to examiners in your area.
The exam checks your vision, hearing, blood pressure, and overall ability to operate a commercial vehicle safely. You will be asked about your medical history, current medications, and any conditions that might affect your driving. The examiner completes a form called the Medical Examination Report (MER), which you submit to your state DMV as part of your CDL process.
Certain conditions can disqualify you or require a waiver: severe vision or hearing loss, uncontrolled diabetes, heart disease, sleep apnea, and some psychiatric medications. You are not automatically disqualified if you have a condition; the examiner determines whether it affects your ability to drive safely. If you are denied, you can seek a second opinion or request a waiver from the FMCSA in some cases.
Your medical certification is valid for a set period — usually two or four years depending on your condition and state rules. You must renew it before your CDL expires, or your license becomes invalid even if the CDL itself has not expired.
Background checks and disqualifying offenses
Your state will conduct a background check before issuing a CDL. Federal law disqualifies you permanently or for a set period if you have certain convictions: felonies involving controlled substances, crimes of violence, or certain traffic offenses (such as driving under the influence or leaving the scene of an accident).
A single DUI conviction typically disqualifies you for at least one year; a second conviction within ten years disqualifies you for life. Felony drug convictions result in permanent disqualification. Some states have additional disqualifying offenses beyond the federal minimum.
You must disclose your driving history and any criminal history on your CDL process. Lying on the process is itself a disqualifying offense. If you have a conviction and are unsure whether it disqualifies you, contact your state's DMV before you explore; they can tell you whether you are may be able to access.
Fees, processing time, and renewal schedules by state
CDL fees vary widely by state. Initial CDL issuance typically costs between $50 and $200, depending on your state and the class and endorsements you are testing for. Some states charge separate fees for the written test, skills test, and medical examination; others bundle them. A few states charge additional fees for background checks or administrative processing.
Processing time from process to receiving your CDL card varies. If you pass all tests on your first attempt, you may receive your license within two to four weeks in many states. If you fail and retake tests, the timeline extends. Some states issue a temporary CDL while you wait for the permanent card; others do not.
Renewal periods are typically four or five years, set by your state. You must renew before your current CDL expires, or you lose the right to drive commercially. Renewal usually requires passing the medical examination again and paying a renewal fee (often $50 to $150). Some states require you to retake the written test; others do not. Check your state's specific renewal requirements on its DMV website.
Frequently Asked Questions
Can I get a CDL if I have a regular driver's license suspension or revocation?
No. You must hold a valid regular driver's license to hold a CDL. If your regular license is suspended or revoked, your CDL is also suspended or revoked. You cannot hold a CDL without a valid underlying regular license in the same state.
Do I need a CDL to drive a truck for personal use, not for work?
No. A CDL is required only if you operate a commercial vehicle for compensation or as part of your job. If you own a truck and drive it for personal use only, you need only a regular driver's license, regardless of the truck's weight. The moment you use it for work — even occasionally — you need a CDL.
What happens if I fail the skills test?
You can retake it. Most states allow you to schedule another test within a set timeframe (often 14 days to a few months). You pay a retesting fee each time. You do not have to retake the written test unless your state requires it or your written test score has expired.
Can I transfer my CDL from one state to another?
You cannot hold a CDL in two states at once. When you move to a new state, you must surrender your old CDL and explore for a new one from your new state of residence. Your new state may recognize your old CDL for a short period while you explore, but you must complete the new state's process, testing, and medical examination to receive a new CDL.
What is the difference between a CDL endorsement and a CDL class?
Your class (A, B, or C) determines the weight and type of vehicle you can drive. An endorsement (like hazmat, passenger, or doubles/triples) adds a specific permission or restriction on top of your class. You can have a Class A CDL with a hazmat endorsement, for example. Each endorsement requires passing an additional written test.