CDL Endorsements Guide
Endorsements expand your CDL capabilities and unlock higher-paying specialty positions. Learn about each endorsement type, requirements, and earning potential.
CDL endorsements are additional qualifications added to your Commercial Driver's License that authorize you to operate specific vehicle types or carry certain cargo. Each endorsement requires passing an additional written knowledge test (and sometimes a skills test). Endorsements are one of the fastest ways to increase your earning potential as a CDL driver — the X endorsement alone can add $8,000 to $20,000 per year to your income.
Endorsement Types
Hazardous Materials (Hazmat)
Authorizes the transport of hazardous materials as defined in 49 CFR 383.5. Required for any load requiring hazmat placards, including chemicals, fuels, explosives, radioactive materials, and compressed gases.
Test Type
Written knowledge test + TSA background check (fingerprints)
Pay Premium
+$5,000 - $15,000/year
Who Needs It
Fuel tanker drivers, chemical haulers, explosives transporters, and any driver whose loads require hazmat placards. Combines with Tanker (N) for the X endorsement.
Tanker
Required to drive any commercial vehicle that transports liquid or gaseous materials in a tank or tanks with an individual capacity of more than 119 gallons and an aggregate capacity of 1,000 gallons or more.
Test Type
Written knowledge test
Pay Premium
+$3,000 - $10,000/year
Who Needs It
Fuel delivery drivers, milk tanker operators, chemical transport drivers, and anyone hauling liquid bulk cargo. Critical for petroleum, dairy, and chemical industries.
Passenger
Required to operate any vehicle designed to transport 16 or more passengers, including the driver. Covers transit buses, charter coaches, and large passenger vehicles.
Test Type
Written knowledge test + skills test with a passenger vehicle
Pay Premium
+$2,000 - $8,000/year
Who Needs It
Transit bus operators, charter bus drivers, tour bus drivers, and airport shuttle operators. Required alongside a Class B CDL for most positions.
School Bus
Required to operate a school bus. Includes all the knowledge areas of the Passenger endorsement plus specific school bus procedures, student management, and emergency protocols.
Test Type
Written knowledge test + skills test with a school bus
Pay Premium
+$2,000 - $6,000/year
Who Needs It
School bus drivers (public and private schools), activity bus drivers, and Head Start/daycare transportation operators. Most districts require additional state-level certifications.
Doubles/Triples
Authorizes the driver to tow double or triple trailers. These combination vehicles require specialized knowledge of coupling, handling, and braking characteristics unique to multi-trailer configurations.
Test Type
Written knowledge test
Pay Premium
+$3,000 - $8,000/year
Who Needs It
LTL (less-than-truckload) drivers for carriers like FedEx Freight, Old Dominion, XPO, and UPS Freight that use double trailers. Some western states allow triple trailers on designated routes.
Combined Tanker + Hazmat
Combines the Hazmat (H) and Tanker (N) endorsements. Required for drivers transporting hazardous materials in tanker vehicles, such as gasoline, diesel fuel, or liquid chemicals.
Test Type
Written knowledge tests for both H and N + TSA background check
Pay Premium
+$8,000 - $20,000/year
Who Needs It
Fuel tanker drivers hauling gasoline/diesel, chemical tanker operators, and liquefied gas transport drivers. This is one of the highest-paying endorsement combinations in trucking.
How to Add an Endorsement
Check eligibility
Ensure you hold a valid CDL (or CLP if adding during initial licensing). For Hazmat, you must be a U.S. citizen or lawful permanent resident.
Study the endorsement material
Review the endorsement-specific sections in your state's CDL manual. Focus on the unique knowledge areas for each endorsement.
Complete ELDT (if required)
First-time Hazmat (H), Passenger (P), and School Bus (S) endorsement applicants must complete ELDT training from an FMCSA-registered provider.
Pass the written knowledge test
Visit your state DMV or authorized testing center. Most endorsement tests are 20-30 questions with an 80% passing score required.
Complete additional requirements
Hazmat requires TSA fingerprinting and background check (allow 4-6 weeks). Passenger and School Bus endorsements require a skills test in the appropriate vehicle type.
Receive your updated CDL
Once all tests and checks are completed, your state DMV updates your CDL with the new endorsement code(s).
Endorsement Summary
| Code | Name | Test Type | Pay Premium |
|---|---|---|---|
| H | Hazardous Materials (Hazmat) | Written knowledge test + TSA background check (fingerprints) | +$5,000 - $15,000/year |
| N | Tanker | Written knowledge test | +$3,000 - $10,000/year |
| P | Passenger | Written knowledge test + skills test with a passenger vehicle | +$2,000 - $8,000/year |
| S | School Bus | Written knowledge test + skills test with a school bus | +$2,000 - $6,000/year |
| T | Doubles/Triples | Written knowledge test | +$3,000 - $8,000/year |
| X | Combined Tanker + Hazmat | Written knowledge tests for both H and N + TSA background check | +$8,000 - $20,000/year |
Ready to Earn More with Endorsements?
Browse hazmat, tanker, and specialized driving positions that pay top dollar for endorsed CDL holders.