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The roar of a semi-truck rolling down the interstate or the steady hum of a city bus weaving through traffic is something most of us overlook. But behind every one of these massive vehicles is a trained professional who keeps the nation moving. These drivers play a crucial role in supporting our economy, and to operate such powerful machines, they need a specialized credential called a Commercial Driver’s License (CDL). In this guide, we’ll break down what a CDL is, why it matters, and the steps involved in earning one.
What is a CDL?
A CDL stands for a Commercial Driver’s License. It is a specialized driver’s license required in the United States—under 49 CFR Parts 300–399—to operate large, heavy, or specialized commercial motor vehicles. Unlike a regular driver’s license, a CDL authorizes drivers to handle commercial vehicles, including 18-wheelers, semi-trucks, tractor-trailers, buses, tankers, and vehicles transporting hazardous materials.
At its core, the CDL’s meaning is tied to safety and federal compliance. While the federal government sets nationwide CDL standards, individual states issue the licenses and may add their own requirements. Anyone who wants to become a professional commercial driver must hold a valid CDL issued by their home state.
History of the CDL
Before 1986, drivers in the United States could operate large commercial vehicles without holding a specialized license. Each state created its own rules for commercial driving, resulting in inconsistent standards and safety concerns nationwide. To improve roadway safety and establish uniform licensing requirements, the federal government passed the Commercial Motor Vehicle Safety Act of 1986.
This law establishes nationwide minimum standards that every state must adhere to when issuing a Commercial Driver’s License (CDL). From that point forward, states could no longer use their own criteria alone—they were required to adopt federal guidelines to ensure that commercial drivers met consistent training and safety expectations.
Another important requirement introduced by the act is that a driver may hold only one driver’s license at any time, regardless of license class. Having multiple licenses is illegal. So, when a driver applies for a Commercial Learner’s Permit (CLP), they must surrender their regular Class F or basic driver’s license as part of the process.
Different types of CDL
CDLs are not one-size-fits-all. They come in different CDL classes —Class A, Class B, and Class C— each based on the vehicle’s size, weight, and purpose. Each CDL class authorizes drivers to operate specific types of commercial motor vehicles. Below is a clear breakdown of each CDL type:
Class A CDL
A Class A Commercial Driver’s License is the top-tier CDL that allows drivers to operate the largest and heaviest combination vehicles. You need a Class A license to drive any combination of vehicles with:
- A Gross Combination Weight Rating (GCWR) of 26,001 pounds or more, and
- A towed unit that exceeds 10,000 pounds
Class A CDL license holders may operate the widest range of commercial vehicles, including:
- Semi-trucks / 18-wheelers
- Tractor-trailers
- Flatbeds
- Dry vans
- Reefers (refrigerated trailers)
- Tanker trailers
- Livestock trailers
- Double and triple trailers
- Truck-and-trailer combinations
- Tractor-trailer passenger buses
Because a Class A CDL covers the heaviest combinations, drivers with this license can also legally operate Class B and Class C vehicles (with the proper endorsements). This makes Class A the most versatile CDL category.
Class B CDL
A Class B Commercial Driver’s License applies to drivers who operate single commercial vehicles that meet the following criteria:
- A GVWR of 26,001 pounds or more, and
- A towed unit that weighs 10,000 pounds or less
Class B CDL license holders can operate large single-unit commercial vehicles such as:
- Straight trucks
- Box trucks and refrigerated delivery trucks
- Dump trucks (with small trailers)
- Cement and utility trucks
- City, tour, and school buses
- Segmented buses
While Class B CDL holders cannot drive Class A combination vehicles, they can operate Class C vehicles when they have the appropriate endorsements.
Class C CDL
A Class C Commercial Driver’s License covers vehicles that don’t meet Class A or Class B criteria, but still require a CDL due to passenger capacity or cargo type. A Class C CDL is required to operate:
- Vehicles designed to carry 16 or more passengers, including the driver
- Vehicles transporting hazardous materials require placards
- Smaller combination vehicles falling under Class A and B weight limits
With the correct endorsements, Class C CDL license drivers may operate:
- Passenger vans
- Small shuttle buses
- Small HAZMAT trucks
- Light trucks towing small trailers
- Specialty vehicles carrying hazardous materials
A Class C CDL is ideal for drivers focused on passenger transport or hazardous materials rather than heavy-haul trucking.
Who needs a CDL?
You must have a Commercial Driver’s License (CDL) if you operate certain types of commercial motor vehicles in the United States. Federal regulations require drivers to hold a CDL when operating vehicles that meet specific weight, passenger, or cargo criteria.
You must obtain a CDL if you operate:
- A single vehicle with a Gross Vehicle Weight Rating (GVWR) of 26,001 pounds or more
- A combination vehicle with a Gross Combination Weight Rating (GCWR) of 26,001 pounds or more, and the towed unit weighs 10,001 pounds or more
- Any vehicle designed to transport 16 or more passengers, including the driver
- Any vehicle transporting hazardous materials that requires placarding under federal guidelines
- Oversized or heavy-duty commercial vehicles, such as those used to haul bulk commodities, large equipment, or large groups of passengers (e.g., school buses)
These requirements ensure that drivers handling heavy, complex, or potentially dangerous vehicles receive the proper training and testing.
CDL license requirements
To qualify for a Commercial Driver’s License, you must meet both federal and state regulations. You must
- Hold a valid non-commercial driver’s license.
- Be at least 18 years old for intrastate driving and 21 years old for interstate driving or transporting hazardous materials.
- Provide proof of lawful U.S. residency.
- Pass all required written knowledge tests.
- Obtain a Commercial Learner’s Permit (CLP) and hold it for at least 14 days before taking the skills test.
- Pass a DOT medical exam.
- Maintain a clean driving record with no active suspensions.
- Be able to read and speak English.
- Complete Entry-Level Driver Training (ELDT) for first-time CDL applicants, upgrades, and certain endorsements (effective February 7, 2022).
Additional TSA clearance is required for H or X endorsements. Some states allow qualified military veterans to waive certain tests with proof of experience.
CDL endorsements
Drivers may need CDL endorsements to operate specific vehicles or transport certain cargo. Endorsements demonstrate extra skills, expand job opportunities, and increase earning potential.
Common CDL Endorsements
- H – Hazardous Materials (HAZMAT): For transporting hazardous materials; requires training, background check, and TSA clearance.
- N – Tank Vehicles: For operating tanker trucks carrying liquids or gases.
- P – Passenger: For vehicles carrying 16 or more passengers, including the driver.
- S – School Bus: Required for transporting students.
- T – Double/Triple Trailers: Allows operation of trucks with two or three trailers.
- X – Tanker + HAZMAT: Combines H and N endorsements for hauling hazardous liquids in tankers.
CDL endorsements make drivers more versatile and employable. Many specialized jobs require specific endorsements, and without them, drivers may face restrictions on their CDL.
Learn more about CDL endorsements
How to obtain a Commercial Driver’s License (CDL)?
To get a Commercial Driver’s License (CDL), start by thoroughly studying your state’s CDL manual to understand the rules, regulations, and requirements. Once prepared, obtain a Commercial Learner’s Permit (CLP), which allows you to practice driving on public roads under the supervision of a qualified CDL holder.
Next, enroll in an entry-level driver training program with a registered training provider to gain hands-on experience and refine your skills. After holding your CLP for at least 14 days, schedule and take the CDL skills test, which includes three critical components: the Vehicle Inspection Test, the Basic Controls Test, and the Road Test.
In addition, ensure you meet the minimum age and medical requirements and acquire any necessary endorsements for specialized driving tasks. Completing these steps demonstrates your expertise, responsibility, and commitment to road safety, unlocking a wide range of commercial driving opportunities.
Ready to hit the road? Know how to get a CDL – step by step.
Frequently asked questions on the CDL license
How long does it take to get a CDL?
The time required to obtain a Commercial Driver’s License (CDL) depends on factors such as the license class, your chosen training schedule, and how quickly you complete the required tests. For most new drivers, the process typically takes 3 to 8 weeks. Accelerated programs can be completed in 3–4 weeks, while part-time study or more extensive training may take up to 6 months to prepare for and pass all tests.
Where is the CDL number located on a license?
The CDL number is usually displayed right at the front of your commercial driver’s license, placed in a clear and easy-to-spot location. However, the exact placement can vary from state to state and may differ based on the license format or issue date.
If you don’t see it on the front, check the back of the card, as some states print an identification “product number” or extended ID there. Regardless of placement, the CDL number will always be clearly marked for identification purposes.
What are the age requirements for a CDL?
The CDL age requirement varies by state and the license class:
- Class A or B CDL: Typically available at 18 years old for intrastate driving; 21 or older is required for interstate (cross-state) driving.
- Class C CDL: Usually available starting at 18 years old.
Are there disqualifications or restrictions for a CDL?
Yes. CDL applicants may be disqualified for reasons including:
- A history of serious traffic violations or criminal offenses
- Medical conditions affecting vision, hearing, or overall physical ability
- Failure to meet state or federal eligibility standards
These CDL restrictions ensure that only qualified drivers operate commercial vehicles safely.
Can you lose your CDL?
Yes. Your CDL can be suspended or revoked if you commit serious traffic violations, criminal offenses, or fail to maintain medical or legal requirements. Losing a CDL also means losing the ability to drive both commercial and, in some cases, non-commercial vehicles under that license.
How much does it cost to get a CDL?
The cost of obtaining a Commercial Driver’s License (CDL) varies by state, but most drivers can expect several standard fees. A Commercial Learner’s Permit (CLP) may cost up to $90, while application fees range from $0–$43. Endorsements typically cost $5–$10 each (not including testing). Written exams may cost up to $125, and the full skills test—covering the road test, pre-trip inspection, and basic controls—can cost as much as $250. After passing all tests, the CDL itself may cost up to $120. Checking your state’s DMV or DOR website will give you the most accurate total.
How hard is it to get a CDL?
Getting a CDL requires preparation, but many applicants find the process manageable with proper study and practice. The written exams are usually straightforward for those who review their state’s CDL manual, use study guides, and take practice tests. Being well-rested and focused on exam day also helps. The skills test—covering vehicle inspection, backing maneuvers, and road driving—can be more challenging, but consistent hands-on practice makes a big difference. The more time you spend training behind the wheel and mastering the pre-trip inspection, the easier it becomes to pass.
