Overview

CDL endorsements are required for commercial drivers to operate specific types of commercial motor vehicles. Additional tests are required to obtain the following federal CDL endorsements:

N Endorsement

The N endorsement allows CDL drivers to operate a tank vehicle (a vehicle that transports liquids or gasses). A written knowledge test is needed to obtain a tank vehicle endorsement.

P Endorsement

The P endorsement is needed to operate a vehicle that seats 16 or more people, including the driver. A written knowledge test is needed to obtain a passenger endorsement.

S Endorsement

The S endorsement allows drivers to operate a school bus. Prior to obtaining an S endorsement, a P endorsement must be earned. A written knowledge test, road skill test, separate application forms, fees, and a background check is required for a school bus endorsement.

T Endorsement

The T endorsement is necessary for CDL drivers looking to tow a double or triple trailer. A written knowledge test is needed to obtain a double/triple trailer endorsement.

X Endorsement

The X endorsement is a combination endorsement for tank vehicles and hazardous materials. A written knowledge test is needed to earn a combination tank vehicle and hazmat endorsement.

A dump truc, a school bus, and a tanker truck