CDL Endorsements and Restrictions Explained

Jul 24 / Erin Ford


Getting your CDL can feel like a complicated process—but it's a necessary one. Commercial motor vehicles (CMVs) come in all shapes and sizes, each with specific safety considerations and skills needed to operate them. CDL endorsements and restrictions determine what you're allowed to drive and under what conditions.

(Just getting started? Check out these posts to learn more about how to get your CDL and how to pay for it!)


What are Endorsements?

Endorsements are special permissions added to your CDL that allow you to operate specific types of vehicles or haul certain loads. Some endorsements require ELDT (Entry-Level Driver Training), while others just require a written test at the DMV.

The chart below breaks down the different endorsements, what’s required to get them, and what they allow you to do:

Endorsement Name

Code

ELDT Required

Test Type

Available On

What It Allows

Doubles/Triples

T

No

Written

CDLs

Drive trucks pulling two or three trailers

Passenger

P

Yes (Theory + BTW)

Written + Driving

CDLs and CLPs

Transport passengers (must be paired with "S" for school buses)

Tanker

N

No

Written

CDLs

Haul liquid or gas tank trailers

HAZMAT

H

Yes (Theory)

Written

CDLs

Haul hazardous materials

HAZMAT + Tanker

X

Yes (Theory)

Written

CDLs

Combination of H and N endorsements

School Bus

S

Yes (Theory + BTW)

Written + Driving

CDLs and CLPs

Drive school buses (must be paired with Passenger endorsement)

 

We offer ELDT theory courses for the Passenger, HAZMAT, and School Bus endorsements, plus study guides for the Doubles/Triples and Tanker endorsements.

You can find approved behind-the-wheel trainers for Passenger and School Bus endorsements using the FMCSA Training Provider Registry.

What Are Restrictions?

Restrictions limit what kinds of vehicles you can operate based on the vehicle you tested in or other conditions (like medical limitations). The good news? Most restrictions can be removed by retaking the proper written or skills test in the appropriate vehicle.

Here’s a quick breakdown:

Restriction Code

What It Means

L

You didn’t pass the air brakes test or didn’t take the skills test in a vehicle with full air brakes. You can’t drive CMVs with full air brake systems.

Z

You tested in a vehicle with an air-over-hydraulic brake system. You’re not authorized to drive CMVs with full air brakes.

E

You tested in a vehicle with an automatic transmission. You’re restricted from driving CMVs with a manual transmission.

O

You tested in a Class A vehicle with a pintle hook or non-fifth wheel connection. You can’t operate Class A vehicles with a fifth wheel connection.

M

You have a Class A CDL but earned your Passenger or School Bus endorsement in a Class B vehicle. You're restricted to operating Class B and C passenger vehicles or school buses.

N

You have a Class B CDL but earned your Passenger or School Bus endorsement in a Class C vehicle. You're restricted to Class C passenger vehicles or school buses.

V

You have a medical variance on file with FMCSA (e.g., vision or insulin use). This must be noted on your CDL and driving record.

Why This Matters

The right endorsements can open doors to better routes, higher-paying jobs, or new specialties. Removing restrictions can help you qualify for more positions and operate a broader range of vehicles. Whether you're just starting out or looking to level up, understanding endorsements and restrictions is key to getting the most from your CDL.

Final Note

Always check with your state DMV or licensing authority—requirements may vary slightly by location.


Check back in to Tuesday's Blog to learn about getting your Class A CDL!