Endorsement
An authorization added to a CDL that allows the holder to operate specific types of vehicles or carry specific cargo. Common endorsements include H (hazmat), N (tanker), T (doubles/triples), P (passenger), and S (school bus).
Endorsements require passing additional knowledge tests and, in some cases, skills tests or background checks. They appear on the CDL as letter codes.
Common CDL endorsements and when each is required
H (HazMat): transporting placarded hazardous materials — also requires a TSA fingerprint background check before issuance. N (Tanker): operating a tanker vehicle with a capacity of 1,000 gallons or more. T (Doubles/Triples): pulling double or triple trailers where permitted. P (Passenger): vehicles designed to transport 16 or more persons including the driver. S (School Bus): operating a school bus — requires additional knowledge and skills testing in most states. X (HazMat + Tanker combo): issued instead of separate H and N when both apply.
Getting and maintaining endorsements
Each endorsement requires passing the applicable CDL knowledge test at the state licensing agency. Some (P, S) also require a skills test. HazMat requires passing the knowledge test AND completing a TSA threat assessment before the endorsement is added to the CDL. Endorsements renew with the CDL. ELDT requirements apply to first-time applicants for the P, S, and H endorsements — training must be completed at a provider on the FMCSA Training Provider Registry.
Last updated: June 4, 2026
When this definition matters
This term usually matters when a driver, owner-operator, or small carrier is deciding whether a federal rule applies, preparing a compliance file, or checking a state CDL step. Use this definition as a starting point, then confirm the controlling requirement in the official source listed below before making a licensing, hiring, dispatch, or recordkeeping decision.
The related terms above are included because they often appear in the same compliance workflow. Reviewing them together can prevent common mix-ups, such as treating a state licensing step as a federal carrier obligation or confusing a driver record with a separate employer record.