The Core 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), hold a valid regular driver's license, and pass a medical examination by a certified medical examiner. You'll also need to pass a written knowledge test specific to the class of CDL you're seeking, a skills test that includes a pre-trip vehicle inspection, a basic control test, and a road test. The exact requirements vary by state, but these core elements are federal standards that every state follows.

Your state's Department of Motor Vehicles (DMV) or equivalent agency administers the CDL program. Before you can test, you must obtain a Commercial Learner's Permit (CLP), which requires passing the written knowledge test and the medical exam. Most states require you to hold the CLP for at least 14 days before you can take the skills test, though some states have longer waiting periods.

Key Takeaways

  • You must hold a valid regular driver's license, be at least 18 years old, and pass a medical exam by a certified examiner before you can get a CDL.
  • The written knowledge test covers vehicle operation, safety rules, and regulations specific to the class of truck or bus you plan to drive.
  • You must obtain a Commercial Learner's Permit first, which requires passing the written test and medical exam, and most states require you to hold it for at least 14 days.
  • The skills test includes a pre-trip inspection, basic vehicle control maneuvers, and a road test with an examiner in the actual vehicle you'll be driving.
  • CDL classes (A, B, and C) have different requirements based on the vehicle's weight and cargo type, so you need to know which class matches your intended work.

Medical Certification and the DOT Physical

The medical examination is not optional and is one of the first hurdles. You must see a certified medical examiner listed on the National Registry of Certified Medical Examiners, maintained by the Federal Motor Carrier Safety Administration (FMCSA). This is not your regular doctor—it must be someone on this specific list. The examiner checks your vision, hearing, blood pressure, and overall health to may support you can safely operate a commercial vehicle.

The medical certificate is valid for up to 24 months, though some conditions may result in a shorter validity period. You'll receive a Medical Certificate (also called a DOT medical card) that you must carry with your CDL. If your medical status changes—for example, if you develop a condition that affects your ability to drive—you must report it and may need to retake the exam.

Written Knowledge Test by CDL Class

The written test is divided into general knowledge and endorsement-specific sections. Every CDL applicant must pass the General Knowledge Test, which covers topics like vehicle inspection, basic control, safe driving practices, and federal regulations. The test typically has 50 questions, and you usually need to score at least 80 percent to pass.

Beyond the general test, you'll take additional tests based on the class of CDL you're seeking. Class A covers combination vehicles (tractor-trailers); Class B covers single large vehicles like buses or dump trucks; Class C is for vehicles carrying hazardous materials or 16 or more passengers. If you want to haul hazardous materials, you'll take a Hazmat endorsement test. If you want to carry passengers, you'll take a Passenger endorsement test. Each endorsement adds another written exam.

Most states allow you to study using the CDL manual they provide free of charge. Some people study on their own; others attend a CDL training school, which typically costs between $3,000 and $7,000 and includes classroom instruction, behind-the-wheel training, and test preparation. Training school is not required by law, but it significantly increases the likelihood you'll pass the skills test on your first attempt.

The Skills Test: Pre-Trip, Control, and Road Test

Once you hold a Commercial Learner's Permit, you can schedule the skills test, which has three parts and must be completed in the same vehicle you'll be driving. The test is administered by your state's DMV or a third-party examiner approved by your state.

The pre-trip inspection requires you to walk around and point out critical components of the vehicle—lights, brakes, tires, mirrors, coupling devices—and explain what you're checking for and why. You don't have to fix anything; you're demonstrating that you know what a safe vehicle looks like. The basic control test takes place in a closed course and measures your ability to back up straight, back up at an angle, and perform a parallel park maneuver. The road test

You must bring the actual vehicle you'll be driving to the test. If you show up in a different truck or bus, you'll be turned away. The vehicle must be in safe working condition and properly registered and insured.

CDL Classes and What Each One Covers

Class A is the most common and covers combination vehicles with a gross vehicle weight rating (GVWR) of 26,001 pounds or more, where the towed vehicle weighs more than 10,000 pounds. This is what most people think of as a tractor-trailer or 18-wheeler. Class A is the highest tier and allows you to drive any commercial vehicle.

Class B covers single vehicles with a GVWR of 26,001 pounds or more, or any vehicle towing a vehicle weighing 10,000 pounds or less. This includes large buses, dump trucks, and cement mixers. Class B drivers cannot drive combination vehicles.

Class C covers vehicles that don't meet the weight requirements for Class A or B but are used to transport hazardous materials or 16 or more passengers. Most Class C licenses are for passenger vans or small hazmat vehicles. You cannot upgrade from Class C to Class A or B; you must test for the higher class separately.

Endorsements and Restrictions

An endorsement is an add-on to your CDL that allows you to drive certain types of vehicles or cargo. The most common endorsements are Hazmat (hazardous materials), Passenger (16 or more people), Tank (tanker vehicles), and Doubles/Triples (double or triple trailers). Each endorsement requires passing an additional written test. Hazmat endorsement also requires a background check and fingerprinting through the Transportation Security Administration (TSA).

A restriction is the opposite—it limits what you can drive. For example, if you fail the air brake portion of the test, you'll receive a restriction that prevents you from driving vehicles with air brakes. Restrictions are common for people who test in automatic-transmission vehicles or who have vision or hearing limitations that don't disqualify them entirely but do limit their scope.

Age, Residency, and State-Specific Rules

You must be at least 18 years old to drive a CDL within your home state only. If you want to drive across state lines (interstate commerce), you must be at least 21. Some states have additional age requirements for certain endorsements—for example, you may need to be 21 to haul hazmat even within your state.

You must be a resident of the state where you're getting your CDL, or at least have a valid address in that state. Most states require you to hold a regular driver's license for a minimum period (often 2 years) before you can get a CDL, though some states waive this if you're under 21. A few states have reciprocity agreements that recognize CDLs from other states, but most require you to test in the state where you live.

Some states impose a waiting period between when you get your Commercial Learner's Permit and when you can take the skills test. This period ranges from 14 days to several months. Check your state's specific rules before you schedule your permit test, because this affects your timeline.

Frequently Asked Questions

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

A DUI or reckless driving conviction does not automatically disqualify you, but it may delay your CDL. Most states require a waiting period after certain violations before you can test. Some violations result in a permanent disqualification. Contact your state's DMV to find out whether your specific violation affects your CDL may be able to access.

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

Training school is not legally required. You can study the CDL manual on your own and take the tests. However, most people who pass the skills test on their first attempt have attended a training school or worked with a professional trainer. Self-study is cheaper but has a lower pass rate.

What happens if I fail the skills test?

You can retake the test, usually within a few days or weeks depending on your state's scheduling. There is typically a fee for each attempt. You must still hold a valid Commercial Learner's Permit to retake the test. Most states allow unlimited retakes, but some cap the number of attempts per year.

How long does it take to get a CDL from start to finish?

If you study on your own and pass both the written and skills tests on your first attempt, you can get a CDL in as little as 2 to 4 weeks. If you attend a training school, the program typically lasts 3 to 7 weeks. If you fail and need to retake tests, add several more weeks. The 14-day minimum holding period for your Commercial Learner's Permit also affects your timeline.

Can I drive a commercial vehicle with a Commercial Learner's Permit?

No. A Commercial Learner's Permit allows you to practice driving a commercial vehicle with a licensed CDL holder in the passenger seat, but you cannot drive commercially or carry cargo for pay. You must have a full CDL to work as a driver.