CDL Endorsements
Expand what you can haul with these additional certifications
CDL Answers Team
Written by CDL holders and exam prep experts · Updated March 2026
CDL endorsements are additional certifications added to your CDL that allow you to operate specialized vehicles or carry specific types of cargo. Each endorsement requires passing a separate written test at the DMV.
All CDL Endorsements
Hazardous Materials (HAZMAT)
Required to transport hazardous materials. Requires a TSA background check and fingerprinting in addition to the written test.
Passenger
Required to drive vehicles designed to carry 16 or more passengers, including buses.
School Bus
Required to drive a school bus. Requires the Passenger (P) endorsement first. Background check required.
Tanker
Required for driving tank vehicles that transport liquids or gases in bulk (over 119 gallons).
Doubles/Triples
Required to pull double or triple trailers. Only available with a Class A CDL.
HAZMAT + Tanker Combined
Combination of H and T endorsements. Required for hauling tanker loads of hazardous materials.
Note: Air Brakes is a restriction removal, not an endorsement
Air Brakes doesn't appear in the endorsement list above because it isn't one. It's the removal of an "L" restriction on a CDL under 49 CFR 383.95 — applied when the driver fails the air brake knowledge test or takes the CDL skills test in a non-air-brake vehicle. Most CMVs use air brakes, so removing the L restriction is essential for nearly all CDL careers.
Read the Air Brakes (L restriction removal) guide →Which Endorsements Should You Get?
It depends on the jobs you want. Here are the most valuable endorsements by career path:
- OTR trucking: HAZMAT (H) and Tanker (T) — or the combo (X) — open the most freight opportunities
- Local delivery: Usually no endorsements needed beyond your base CDL
- Bus driver: Passenger (P), plus School Bus (S) if driving school routes
- Fuel/chemical hauling: HAZMAT + Tanker (X endorsement) is required
HAZMAT Background Check
The HAZMAT endorsement requires a TSA Security Threat Assessment with fingerprinting at an IdentoGO enrollment center, an $86.50 federal fee (at UES centers), and 60+ days lead time before you need the endorsement. Disqualifying offenses are listed in 49 CFR 1572.
For the full process — disqualifications, renewal cycles, state fees, and step-by-step application — see the HAZMAT Endorsement Guide.
Practice endorsement tests for free
CDL Answers covers all endorsement tests with real exam questions and detailed explanations.
Free Practice TestsRelated Guides
Doubles/Triples Endorsement: Complete 2026 Guide
Coupling sequence, off-tracking, the STAA highway network, and state legality — everything to add the T endorsement on a Class A CDL.
Air Brakes (L Restriction Removal): Complete 2026 Guide
The 7-step pre-trip air brake check, low-air warning thresholds, spring brake activation, and how to remove the L restriction from your CDL — under 49 CFR 383.95.
CDL Classes Explained
Understand Class A, B, and C CDL requirements and vehicle types.