Understanding the types of CDLs
CDLs are split into three different classes. The class of your license dictates the type of vehicles you’re legally allowed to drive.
CDL classes are defined by two different weight ratings:
- Gross vehicle weight rating (GVWR): The amount of weight that a vehicle or trailer can carry safely.
- Gross combination weight rating (GCWR): The total maximum weight of the vehicle, occupants, trailer and cargo.
Every CDL class has its own GVWR and GCWR requirements, and it’s important to know the difference before you apply. Keep in mind that the following are the minimum CDL rules set by the federal government. Your state might have tighter restrictions.
Class A licenses
The Class A CDL is designed for heavyweight tow vehicle/trailer combinations. It permits you to operate a combination of vehicles with a GCWR of 26,001 pounds or greater. With a Class A CDL, you’re also allowed to tow a trailer or vehicle with a GVWR 10,001 pounds or more.
A Class A CDL is the most versatile option for commercial drivers because it has the highest weight limits. If you have the correct endorsements, you can also use this license to operate a Class B or Class C vehicle.
Class B licenses
If you have a Class B CDL, you can legally drive a standalone vehicle with a GVWR of 26,001 pounds or more. You can also tow a trailer or vehicle, as long as it has a GVWR of 10,000 pounds or less. With the right endorsements, a Class B CDL also permits you to drive Class C vehicles.
Class C licenses
You’ll need a Class C CDL to operate vehicles that don’t fit into Class A or Class B. This includes:
- Any commercial vehicle with a GVWR that’s less than 26,001 pounds
- Vehicles that are designed to carry 16 people or more
- Vehicles that are used to carry hazardous materials
Your state may also require a Class C CDL if you’re transporting students. In Connecticut, for example, you need this license for vehicles that carry more than 10 people—but only if you’re using that vehicle to drive people younger than 21 to and from school. This scenario also requires you to have a V endorsement.
What is a CDL endorsement?
CDL endorsements are certifications that are added to your license. They verify you have the skills and legal permission to operate specialized commercial vehicles, such as school buses. To get an endorsement, you must pass a knowledge test and/or a driving test. Each one has its own requirements.
Endorsements aren’t limited to full-fledged CDLs. You may also be able to add them to your commercial learner’s permit (CLP). This is most common among aspiring tanker drivers—if you have the N endorsement on your CLP, you can practice driving an empty tanker truck with a commercially licensed driver. The same goes for the S and P CLP endorsements, which allow you to drive empty school buses or passenger vehicles.
Types of CDL endorsements
The federal government lays out the basic requirements for six different commercial license endorsements.
T endorsement
Get the T endorsement, often referred to as doubles and triples, if you plan to pull two or three trailers. You might need it for long-distance cargo hauling, towing or construction work. Some states, including Michigan, don’t allow triple-trailer configurations. In that case, your endorsement will only cover a double-trailer setup. You can get the T endorsement by passing a knowledge test. It’s only available when you have a CDL; federal law prohibits it for CLPs.
P endorsement
You’ll need the P commercial license endorsement if you want to drive a commercial vehicle that’s designed for 16 or more people. This number includes the driver. P endorsement is useful for commercial bus drivers, shuttle drivers and school bus drivers. The application process usually includes a knowledge test and a skills test.
N endorsement
This endorsement enables you to drive commercial vehicles with tanks that hold liquid or gas. In most states, you’ll need it if the total volume of all tanks is more than 1,000 gallons or if individual tanks can hold over 119 gallons. This endorsement is usually available for all CDL classes, and it requires a knowledge test.
H endorsement
The H endorsement allows you to transport hazardous materials. It’s only required for volumes or substances that require placards under the Department of Transportation (DOT) rules. This endorsement involves a knowledge test.
X endorsement
The X endorsement is a hybrid of the N and H endorsements. It enables you to carry hazardous liquids or gasses in a tanker truck. In most states, you can also use the X endorsement to carry nonhazardous materials in a tank. It also requires a knowledge test.
S endorsement
This endorsement is limited to school bus drivers. You need it for any commercial vehicle that’s used to carry students between home and school. It also applies if you’re transporting students to any events that are sponsored by the school, such as field trips, band competitions or sporting events. Students may be in preschool, primary or secondary school. In addition to a skill and knowledge test, most states also require you to have a good driving record and a background check.
State specific CDL endorsements
Each state has the freedom to create its own set of endorsements, in addition to those listed above. Some states take advantage of this ability, while others don’t. Examples of additional endorsements are:
- Farm endorsements: Many states offer specific CDL endorsements for farm vehicles. In New York, the F and G endorsements can be added to Class A and Class B CDLs. In Michigan, you can get a farm endorsement on a Class B or Class C CDL; the requirement is waived if you have a Class A license.
- Recreational vehicle endorsements: Depending on your place of residence, you may need a special endorsement for your RV. Class C CDL holders in California need a fifth-wheel recreational trailer endorsement for rigs between 10,001-15,000 pounds.
- Air brakes: This endorsement is designed for commercial vehicles with air brakes. In most states, it’s covered under restrictions. However, some states, such as New Hampshire, have designated endorsements.
What’s the difference between CDL restrictions and endorsements?
While CDL endorsements allow you to drive more types of vehicles, restrictions place limits on your driving. Restrictions are applied to your CDL after you take the knowledge and skills test. You may get them if you fail to take or pass specific knowledge or skills tests.
Restrictions can also be based on the vehicle you use for your CDL skills test. For example, if you complete the Class A road test in a vehicle that does not have a fifth-wheel connection, you’ll get the O restriction. It prevents you from driving fifth-wheel Class A setups.
The best way to avoid CDL restrictions is to consider the type of vehicle you want to drive for work. Then, take your CDL test in the same type of vehicle. This is particularly important if you’re planning to drive school buses or vehicles with air brakes.
Common CDL restrictions:
- E: No manual transmissions
- L and Z: No vehicles with full air brakes
- V: Indicates that you have a medical variance
- M: You can only drive school buses and passenger vehicles if they are Class B or Class C
- N: If you want to drive a passenger vehicle or school bus, it must be Class C
- K: Intrastate travel only
How to get CDL endorsements
Both CDLs and CDL endorsements are administered at the state level. You must get a CDL in your state of residency. Then you can take the skills and knowledge tests for specific endorsements. If you’re applying for a new CDL, it’s often most efficient to test for endorsements at the same time, ideally while you’re handling other business licensing and insurance tasks.
If you already have a CDL, the process for earning endorsements is straightforward:
- Make a testing appointment with your local Department of Motor Vehicles or Secretary of State office
- Pay the fee for the endorsement
- Take the knowledge test on the office computers
- If necessary, schedule and pass a road skills test
- Wait for your new CDL to arrive in the mail; it will be printed with your new endorsement
Some endorsements have a longer timeline. The H endorsement is a prime example. Since it enables you to transport dangerous substances, you’ll need to jump through a few extra hoops. Before you’re allowed to apply and test, you must pass the Hazardous Materials Endorsement Threat Assessment Program. During your appointment, officials will take your fingerprints and ask for documentation proving you’re an American citizen or a lawful permanent resident. The background-check process takes an average of 30 days.
