CDL Endorsement Practice Tests
An endorsement is an extra qualification added to your CDL that lets you operate a specific kind of commercial vehicle or carry a specific kind of cargo. Each endorsement has its own knowledge exam. Below are the eight endorsement categories covered on this site, in the order most drivers pursue them.
General Knowledge
The foundation test required for every CDL applicant, regardless of class or endorsement.
RequiredAir Brakes
Required to legally operate any commercial vehicle equipped with air brakes — most trucks.
EndorsementCombination Vehicles
Required for Class A drivers operating any combination of vehicles (tractor-trailer).
EndorsementHazmat
The H endorsement, required to transport hazardous materials in placardable amounts.
EndorsementTanker
The N endorsement, required to haul liquid or gaseous loads in bulk tanks.
EndorsementDoubles/Triples
The T endorsement, required to pull two or three trailers behind a single tractor.
EndorsementPassenger
The P endorsement, required for buses and other vehicles designed to carry 16+ people.
EndorsementSchool Bus
The S endorsement, required (in addition to P) to drive a school bus.
Which endorsements do I actually need?
For most new commercial drivers, the path looks like this: General Knowledge + Air Brakes + Combination Vehicles for a Class A, or General Knowledge + Air Brakes for a Class B. Beyond that, the endorsements you add depend on the job:
- Hazmat (H) — required for any load of hazardous materials in placardable quantities. Also requires a TSA background check.
- Tanker (N) — required for liquid or gaseous bulk loads of 1,000+ gallons in tanks 119+ gallons.
- Doubles/Triples (T) — required to pull two or three trailers.
- Passenger (P) — required for any vehicle designed to carry 16+ people including the driver. Buses, shuttles, motorcoaches.
- School Bus (S) — required, in addition to Passenger, to drive a school bus.
Combine endorsements as your job requires. A typical fuel-hauler, for example, holds H + N (often written X for the combined Hazmat + Tanker endorsement). A coach driver holds P. A school bus driver holds P + S.