CDL Endorsements and Restrictions in Colorado

Commercial drivers in Colorado must obtain the appropriate endorsements and avoid certain restrictions to operate specific types of commercial vehicles legally. Endorsements authorize drivers to transport particular cargo or operate specialized vehicles, while restrictions limit driving privileges based on skills, vehicle type, or licensing status.

Understanding CDL Endorsements

Endorsements are added to a CDL after passing specialized knowledge or skills tests. Here are the primary CDL endorsements available in Colorado:

• T — Double/Triple Trailers: Required for operating vehicles with double or triple trailers. A knowledge test is mandatory.
• P — Passenger Transport: Required to operate vehicles designed to carry 16 or more passengers, including the driver. It includes both a written test and a skills test in the type of vehicle you plan to drive.
• N — Tank Vehicles: Required for operating tanks that carry liquid or gaseous materials. This involves a written test only.
• H — Hazardous Materials (HazMat): Required for transporting hazardous materials. Drivers must pass a knowledge test and undergo a federal Transportation Security Administration (TSA) background check.
• X — Combination of Tank and HazMat: Combines both N and H endorsements.
• S — School Bus: Required for driving a school bus. This endorsement involves both a written and skills test and a background check specific to school bus drivers.

Adding endorsements requires obtaining a CDL in Colorado, and the testing standards are aligned with the Federal Motor Carrier Safety Administration (FMCSA) requirements.

CDL Restrictions in Colorado

Restrictions are placed on a CDL to indicate limitations on what the holder is allowed to do. Common restrictions include:

• E — No Manual Transmission: Applies if the skills test was taken in a vehicle with an automatic transmission.
• K — Intrastate Only: Indicates the driver may only operate commercially within Colorado.
• L — No Air Brake Equipped CMV: Assigned if the driver fails the air brake component of the knowledge or skills test or takes the test in a vehicle without air brakes.
• M — No Class A Passenger Vehicle: Indicates the driver is not authorized to operate Class A passenger vehicles.
• N — No Class B Passenger Vehicle: Similar to M but for Class B vehicles.
• O — No Tractor-Trailer CMV: Assigned when the skills test was not performed in a tractor-trailer.

These restrictions are based on the vehicle used during testing or specific limitations of the driver’s license type. To remove a restriction, a driver must retest under proper conditions.

How to Add or Remove Endorsements and Restrictions

To add an endorsement or remove a restriction, follow these steps:

1. Schedule an appointment at a Colorado DMV office authorized to issue CDLs.
2. Prepare for the required tests, which may include a written knowledge test, a skills test, or both. You can use state-approved prep resources such as the Colorado Driver’s License Eligibility Guide.
3. Bring the appropriate identification and documents, including proof of legal presence, residency, and Social Security number.
4. Pay applicable fees, which vary depending on the endorsement type or restriction removal.
5. For HazMat endorsements, complete a TSA background check through the TSA’s Hazmat Endorsement Threat Assessment Program.

For more information on required medical evaluations for CDL holders, refer to the Medical Requirements for Colorado CDL Holders.

Keep Your CDL Updated

CDL holders must ensure their license reflects their current qualifications. Keeping your endorsements valid and restrictions accurate ensures compliance with state and federal laws, prevents penalties, and promotes road safety.

To explore all aspects of licensing, including REAL ID, see How to Get a REAL ID in Colorado.