N
Washington Endorsement
CDL endorsement code N
Required to drive a tank vehicle carrying liquid or gaseous cargo.
What it covers
The Tank (N) endorsement is required to drive a vehicle hauling liquid or liquefied gas in a tank with rated capacity of 119 gallons or more (or aggregate ≥ 1,000 gallons) that is permanently or temporarily attached to the vehicle.
Federal requirements
- Pass the Tank vehicles knowledge test (~20 questions).
- No TSA background check or skills test required.
- Renews with your CDL.
Source: 49 CFR §383.93(c)(3)
Fees
Knowledge-test fee only ($5-$25 in most states).
How to study
- Read the Tank section of your state CDL manual.
- Focus on liquid surge, baffled vs unbaffled tanks, and high center of gravity.
- Practice with the Tank practice test inside your state's page.
Take the Washington practice test
State-specific practice tests live inside each state hub. Pick yours:
FAQ
What's the difference between baffled and unbaffled tanks?
Baffled tanks have internal bulkheads that limit forward-and-back liquid surge. Unbaffled (smooth-bore) tanks need extra care during stops and starts because liquid can slam the driver forward.
Does Tank require ELDT?
No — N is not in the ELDT-required endorsement list.