A CDL lets you drive trucks and buses for work — and requires different testing than a regular license
A Commercial Driver's License (CDL) is a separate license issued by your state that permits you to operate vehicles over a certain weight or designed to carry passengers for compensation. You cannot legally drive a semi-truck, dump truck, or passenger bus for work with only a standard driver's license, even if you own the vehicle. The CDL replaces your regular license while you hold it and requires you to pass knowledge tests and a skills test specific to the type of vehicle you will operate.
The process takes weeks to months depending on your state and how quickly you complete the steps. You will need to study the CDL manual for your state, pass a written exam on traffic laws and vehicle operation, and then pass a behind-the-wheel driving test with an examiner. Some states allow you to take the written test at a DMV office; others require you to go through a CDL testing facility or a truck driving school.
Key Takeaways
- You must obtain a CDL before driving any commercial vehicle for work, and the requirements vary by state and by the type of vehicle you plan to operate.
- The written test covers traffic laws, vehicle inspection, and safe driving practices specific to large trucks or buses, and you must score at least 80 percent on most state exams.
- The skills test includes a pre-trip vehicle inspection, a backing and maneuvering exercise, and a road test, all performed in the actual type of vehicle you will drive.
- Medical certification through a Department of Transportation (DOT) physical is required before you can be issued a CDL, and your health status may disqualify you from certain vehicle classes.
- Truck driving schools can prepare you for the CDL tests in weeks, but you can also study independently and test through your state's DMV if you already have driving experience.
CDL classes and what vehicle types each one covers
Your state issues three main CDL classes — A, B, and C — based on the vehicle's Gross Vehicle Weight Rating (GVWR) and whether it carries passengers. Class A covers the heaviest trucks, including semi-trucks and tractor-trailers, and allows you to tow trailers weighing over 10,000 pounds. Class B covers single vehicles over 26,001 pounds, such as dump trucks, concrete mixers, and large buses. Class C covers smaller vehicles that carry 16 or more passengers (like shuttle buses) or vehicles carrying hazardous materials.
Within each class, you can add endorsements that permit you to operate specific vehicle types or carry certain cargo. The most common endorsement is Hazmat (H), which allows you to transport hazardous materials and requires a separate written test and a Transportation Security Administration (TSA) background check. Other endorsements include Tanker (N) for vehicles carrying liquids, Passenger (P) for buses, and Double/Triple Trailers (T) for tractor-trailers with multiple trailers.
You do not need to obtain all endorsements at once. Many drivers start with a Class A CDL and add endorsements later as their job requires them. Each endorsement requires passing an additional written test but not necessarily a new skills test.
The written test: what to study and how to prepare
The CDL written test is divided into sections covering general knowledge, air brakes (if your vehicle has them), and any endorsements you are pursuing. The general knowledge section tests your understanding of traffic laws, vehicle inspection, load securement, and safe driving practices for large vehicles. Most states require you to score at least 80 percent to pass each section.
Your state's CDL manual is the primary study resource and is available free online from your state's DMV website. The manual covers topics like how to inspect your vehicle before driving, how to handle brake failure, how to safely back up a large truck, and how to find cargo. Many drivers also use third-party study apps and practice tests, which can help you identify weak areas before you take the official exam.
The air brakes section applies only if you will drive a vehicle with air brakes. If your vehicle has hydraulic brakes instead, you can skip this section. However, if you pass the test without taking the air brakes section, your CDL will carry an air brakes restriction, meaning you cannot legally drive vehicles with air brakes.
The skills test: vehicle inspection, backing, and road driving
The skills test has three parts, all performed in the actual type of vehicle you will operate. First, you perform a pre-trip vehicle inspection, where you walk around and inside the truck or bus and point out or test critical components — lights, mirrors, tires, brakes, coupling devices, and safety equipment. The examiner watches and listens as you explain what you are checking and why. You do not need to fix anything; you just need to demonstrate that you know what to look for and what would make a vehicle unsafe to drive.
Second, you complete a backing and maneuvering exercise in a closed course. This typically involves backing the vehicle in a straight line, backing into an alley or dock, and performing a 90-degree turn. The examiner scores you on your ability to stay within marked boundaries and use mirrors and spotters correctly.
Third, you take a road test lasting 30 to 60 minutes, depending on your state. You drive on public roads while the examiner observes your ability to accelerate, brake, turn, merge, and navigate traffic safely. The examiner may ask you to perform specific maneuvers, such as a lane change or a hill start, to test your control of the vehicle.
DOT medical certification and health requirements
Before you can receive a CDL, you must pass a Department of Transportation (DOT) physical examination performed by a certified medical examiner. The examiner checks your vision, hearing, blood pressure, and overall health to may support you can safely operate a large vehicle. You must have at least 20/40 vision in each eye (with or without correction) and be able to hear a whispered voice at three feet away.
Certain medical conditions can disqualify you from holding a CDL or limit the type of vehicle you can drive. These include uncontrolled diabetes, heart disease, sleep apnea, and some psychiatric conditions. If you have a condition that might affect your may be able to access, discuss it with the medical examiner before the exam. Some conditions are temporary; others may require you to pursue a waiver from your state.
The DOT medical certificate is valid for two years (or one year if you are over 60 and drive interstate). You will need to renew it before your CDL expires. The cost of a DOT physical varies by location but typically ranges from $100 to $200.
Truck driving school versus independent study and testing
You have two main paths to obtaining a CDL: enroll in a truck driving school or study independently and test through your state's DMV. Truck driving schools typically offer programs lasting four to eight weeks and include classroom instruction, behind-the-wheel training, and test preparation. Many schools have partnerships with testing facilities, so you can take your skills test at the school rather than scheduling a separate appointment at a DMV office. Schools also provide the vehicle for your skills test, which is helpful if you do not own a commercial vehicle.
The cost of truck driving school ranges from $3,000 to $7,000, depending on the program length and location. Some schools offer financing or payment plans. Many trucking companies offer tuition reimbursement or cover the cost of training if you commit to working for them for a set period.
Independent study is an option if you already have significant driving experience and feel confident learning on your own. You study the CDL manual, take practice tests, and schedule your written and skills tests through your state's DMV. This route is cheaper — you only pay the test fees, which vary by state but typically total $100 to $300 — but you must arrange your own vehicle for the skills test and schedule your own testing appointments, which can take longer.
State-by-state differences in testing and fees
CDL requirements and testing procedures vary by state. Some states allow you to take the written test at any DMV office; others require you to test at a dedicated CDL testing facility. Some states offer the written test in multiple languages; others offer it only in English. Testing fees range from $50 to $150 per test, depending on your state.
The skills test is more standardized across states but still has variations. Some states allow you to use a school's vehicle for the test; others require you to use a vehicle registered to you or your employer. Some states offer the skills test on weekends or evenings; others only during business hours. Check your state's DMV website for the specific requirements, testing locations, and current fees before you begin studying.
If you move to a different state while holding a CDL, you can transfer it to your new state's DMV without retesting, as long as you meet that state's medical and licensing requirements. However, if your new state has different endorsement rules or restrictions, you may need to take additional tests to add or modify endorsements.
Frequently Asked Questions
Do I need a CDL to drive a pickup truck or van for work?
No, not unless the vehicle's GVWR exceeds 26,000 pounds or it is designed to carry 16 or more passengers. Most pickup trucks and vans fall below this threshold. Check your vehicle's registration or door placard to find the GVWR. If you are unsure, contact your state's DMV.
Can I take the CDL written test without attending truck driving school?
Yes. You can study the CDL manual on your own and take the written test at your state's DMV or testing facility. However, you will still need to pass the skills test, which requires access to the appropriate commercial vehicle and a certified examiner.
What happens if I fail the skills test?
You can retake the test after waiting a set period (usually one to seven days, depending on your state). You pay the test fee again each time you retake it. Most people pass on their second or third attempt. Truck driving schools often include retake opportunities in their programs.
How long does a CDL stay valid?
A CDL is valid for four to eight years, depending on your state and age. You must renew it before it expires by passing a written test and a medical examination. Some states allow you to renew by mail or online if you have no violations.
Can I get a CDL if I have a DUI or traffic violations on my record?
A DUI or serious traffic violation does not automatically disqualify you, but it may delay your process or require additional review by your state's DMV. Contact your state's DMV to discuss your specific situation before you begin the CDL process.