CDL Class B Practice Test 2026 — Free Permit Prep
A Class B CDL (federally, “Group B — heavy straight vehicle”) covers any single vehicle with a GVWR of 26,001 pounds or more, including one towing a vehicle rated 10,000 pounds or less. Straight trucks, dump trucks, box trucks, and large buses typically fall in this class — the towed-unit limit is what separates it from Class A.
50 questions · 80%
Every CDL applicant must pass the general knowledge test before a commercial learner’s permit can be issued — it covers the 20 knowledge areas all commercial drivers are tested on.
49 CFR 383.71(a)(2), 383.111
25 questions · 80%
Most Class B vehicles use air brakes. Fail the air brake knowledge component (or test in a vehicle without them) and your license carries a restriction against operating any air-braked vehicle.
49 CFR 383.95(a), 383.135(a)(2)
80%
Passing score (every test)
18 / 21
Min. age — in-state / interstate
14
Days holding permit before road test
50
General Knowledge questions
The 80% passing score is a federal standard (FMCSA, 49 CFR 383.135). Question counts follow the AAMVA model used by most states and can vary by state. Always confirm current details with your state's official CDL handbook.
CDL General Knowledge Practice Test
What a Class B CDL lets you drive
A driver who has passed the Class B knowledge and skills tests may also operate Class C vehicles with the requisite endorsements — but not Class A combinations. Driving a bus additionally requires the passenger endorsement, and a school bus the S endorsement.
49 CFR 383.91(c)(2)
Entry-Level Driver Training (ELDT) is required first
If you got (or will get) your commercial learner’s permit on or after February 7, 2022, federal rules require you to complete Entry-Level Driver Training from a provider listed in FMCSA’s Training Provider Registry before you can take the CDL skills test for a first Class A or Class B license. Drivers issued their CDL before that date are not required to complete ELDT for that license.
FMCSA Training Provider Registry49 CFR 380.603
CDL Class B — frequently asked questions
What is the difference between Class A and Class B?
Both start at a 26,001-pound rating, but Class A is a combination whose towed vehicle(s) are rated over 10,000 pounds, while Class B is a single vehicle of 26,001+ pounds towing at most 10,000. If you plan to pull heavy trailers, you need Class A; a Class B cannot be upgraded without retesting.
49 CFR 383.91(a)(1)–(2)
Which knowledge tests does Class B require?
General knowledge is required of every applicant before the learner’s permit. Air brakes is effectively required for most Class B vehicles — skipping or failing it puts an air-brake restriction on your license. The combination vehicles test is a Class A requirement, not Class B.
49 CFR 383.71(a)(2), 383.95(a)
What score do I need to pass?
At least 80% on each knowledge test — a federal standard, the same in every state. Question counts follow the AAMVA model most states use; confirm your state’s counts in its official CDL handbook.
49 CFR 383.135(a)(1)
Can I drive a school bus with a Class B?
A Class B covers the vehicle size of most school buses, but carrying passengers requires the P endorsement and a school bus specifically requires the S endorsement, each with its own knowledge and skills tests.
49 CFR 383.91(c)(2), 383.93
Practice the Class B test by state
Official sources
- 49 CFR 383.91 — Commercial motor vehicle groups
- 49 CFR 383.135 — Passing knowledge and skills tests
- 49 CFR 383.95 — Restrictions
- FMCSA — Entry-Level Driver Training (Training Provider Registry)
Federal rules verified against the eCFR on 2026-09-02.