A commercial Driver’s License (CDL) is a license specific to driving certain specialized types of vehicles such as buses or tank trucks. This can include heavy, oversized vehicles and those that carry multiple passengers. Some types of CDL licenses and endorsements are used to transport hazardous materials like flammable liquids, explosives, or radioactive substances.
Every truck driver needs to have some type of CDL. Whether you see yourself as a long-haul trucker, a school bus driver, or piloting the motor coach for a rock band, you’ll need the right CDL for the job. Although CDL requirements vary by state, what follows is an overview of much of the general information you need to know.
There are three different types of CDL licenses: Class A, B, and C.
A Class A CDL allows you to drive a vehicle or any combination of vehicles with a gross combination weight rating (GCWR) of 26,001 pounds, or more. This includes towed unit(s) with a gross weight rating (GVWR) of more than 10,000 lbs.
With a Class A CDL, you may be able to drive:
Tractor-trailers and flatbeds
Truck and trailer combinations (double and triple trailers)
A Class B CDL allows you to drive a vehicle with a GVWR of 26,001 lbs or more. If you are towing, the GVWR of the vehicle being towed may not exceed 10,000 pounds.
With a Class B CDL, you may be able to drive:
Large buses, including city buses and tourist buses
Box trucks (delivery drivers, couriers, and furniture delivery)
Dump trucks with small trailers
A Class C CDL allows you to drive a single or combination vehicle designed to transport specific quantities of passengers. It also allows you to drive vehicles containing materials that may be considered dangerous and may not meet other CDL classifications, with the appropriate endorsements.
With a Class C CDL, you may be able to drive:
Small HAZMAT vehicles
Small truck towing a trailer
The most common CDL class is a class A.
In addition to the different types of CDL licenses in Class A, B, or C, you may need to take additional written or road tests to be qualified to operate special types of vehicles that your job requires. These tests give you your CDL endorsements in driving specific types of vehicles that are special or dangerous for a variety of reasons. A few different types of CDL endorsements include being able to safely transporting hazardous materials, towing more than one trailer, or operating a school bus.
Each one of these individual tests and qualifications is a type of endorsement you can earn as a CDL driver. Here is a full list of available CDL endorsements, and information about each one.
A Commercial Learner’s Permit (CLP) is exactly like a learner’s permit you get when you first start driving. It gives you the ability to practice driving for your CDL driving test. After passing a written test at the DMV, you will earn your CLP. Your CLP allows you to practice and train as a driver, for up to 180 days, as long as a person with a valid CDL is driving with you.
You must get your CLP first before you get your CDL. After a minimum of 18 days of having your CLP, you will be able to take your test to earn your CDL.
To go through a few free practice quizzes and tests for either your CLP or CDL, we have provided that with a bit of information about each exam.
Here are some examples of restrictions that might impose special requirements on drivers seeking a Commercial Driver’s License. For example, a driver may be prohibited from operating a manual transmission if the skills test was performed on a vehicle with an automatic transmission. Other restrictions include the following:
B – Corrective lenses
C – Mechanical aid
D – Prosthetic aid
E – Automatic transmission only
F – Dual outside mirror
G – Daylight only operation
K – CDL intrastate only
L – Vehicles without air brakes
M – Group B or Group C passenger vehicles
N – Group C passenger vehicles only
O – No fifth wheel (combination vehicles)
P – Commercial Learner's Permit Only. No passengers other than trainer, additional trainees or test examiner
U – Hearing aide required
V – Medical variance required
W – Medical waiver required
X – Commercial Learner's Permit Only. No cargo in tank vehicle and tank must be purged. Restricts "N" endorsement
Z – No full air brake-equipped commercial motor vehicle
In general, having a restriction on your CDL means you are limited to which vehicles and/or equipment you are authorized to drive. The M restriction is for a Class A CDL, but means that you obtained your passenger or school bus endorsement in a Class B vehicle.
If you have the M restriction you are only allowed to operate a Class B or Class C passenger vehicle or school bus. While you do have a Class A CDL, you are not able to operate any class A passenger vehicle.
To remove this restriction, you will have to refer to your state’s regulations and laws as not all states have the same restrictions.
Are you still asking yourself “what is a CDL?” The information on this page is intended to provide an overview, since requirements vary by state. For a deeper dive into, CDL classifications, more information about earning a Commercial Driver’s License in your State and necessary medical certifications, visit the CDL.com State Requirements page or FMCSA site for more information.