CDL Test 2026: Knowledge Tests, Classes and Skills Test

What is the CDL test?

It is the set of state-run tests you pass to get a commercial driver's license: written knowledge tests for a permit, then a vehicle inspection, basic control and road test for the license itself.

A CDL is required to drive a commercial motor vehicle above the weight or passenger limits in the federal rules. The Federal Motor Carrier Safety Administration (FMCSA) sets the minimum standards in 49 CFR Part 383, and each state runs its own testing under them, using a state CDL manual built on a common national model.

People usually say "the CDL test" for the written knowledge tests, because that is the first hurdle and the one you study for at home. This page covers both stages; the free CDL practice test covers the knowledge tests.

The real knowledge tests, with where each fact comes from
Who gives them	Your state licensing agency (DMV, DOL or BMV), under federal rules in 49 CFR 383Published by the ownerFMCSA, "Commercial Driver's License"
Tests for a Class A permit	General Knowledge, Air Brakes and Combination Vehicles, plus any endorsement tests you wantPublished by the ownerWashington State Department of Licensing, "CDL knowledge test"
Questions	General Knowledge 50, Air Brakes 25, Combination Vehicles 20 in Washington; some states ask 20 Air Brakes or 25 Combination questionsPublished by the ownerWashington State Department of Licensing, "CDL knowledge test"
Pass mark	At least 80% on each test, scored separatelyPublished by the ownereCFR, 49 CFR 383.135, passing knowledge and skills tests
Format	Multiple choice, usually on a computer at the licensing officePublished by the ownerWashington State Department of Licensing, "CDL knowledge test"
Time limit	Set by each state; many do not time each test tightly, but check your state's rulesSourcedWashington State Department of Licensing, "CDL knowledge test"
What you get	A commercial learner's permit (CLP), which you must hold for 14 days before the skills testPublished by the ownereCFR, 49 CFR 383.25, commercial learner's permit

Which CDL class do I need?

Class A for combinations over 26,000 lb where the trailer is rated over 10,000 lb, Class B for single vehicles over 26,000 lb, and Class C for smaller vehicles that carry 16 or more people or placarded hazardous materials.

CDL classes from 49 CFR 383.91 (weights are ratings, not what the vehicle weighs today)
Class	What it covers	Typical vehicles
Class A	A combination with a gross combination weight rating (GCWR) of 26,001 lb or more, where the towed unit is rated over 10,000 lb	Tractor-trailers, truck and trailer combinations, tankers and flatbeds behind a tractor
Class B	A single vehicle rated 26,001 lb or more, or one towing a unit rated 10,000 lb or less	Straight trucks, large buses, dump trucks, box trucks over 26,000 lb
Class C	Neither A nor B, but built to carry 16 or more people including the driver, or carrying placarded hazardous materials	Small passenger vans and buses, small hazmat vehicles

A Class A license lets you drive Class B and C vehicles too, provided you hold the endorsements those vehicles need. The ratings that matter are the manufacturer's GVWR and GCWR, not the scale weight, which is why a light-looking pickup towing a heavy-rated trailer can need a Class A.

What knowledge tests do I need for a CDL?

Everyone takes General Knowledge. Add Air Brakes if your vehicle has air brakes, Combination Vehicles for Class A, and an endorsement test for each special type: hazmat, tanker, passenger, school bus or doubles and triples.

The Class A permit tests, Washington's published counts
Test	Questions	Correct to pass	Who takes it
General Knowledge	50	40 (80%)	Everyone, for every class
Air Brakes	25	20 (80%)	Anyone driving a CMV with air brakes (or you get an air brake restriction)
Combination Vehicles	20	16 (80%)	Class A applicants

Endorsements from 49 CFR 383.93
Code	Endorsement	What it needs
H	Hazardous materials	Knowledge test plus a TSA security threat assessment
N	Tank vehicles	Knowledge test
P	Passenger vehicles	Knowledge and skills tests
S	School bus	Knowledge and skills tests, plus the passenger endorsement
T	Double and triple trailers	Knowledge test
X	Tank vehicle carrying hazardous materials	Both the H and N tests

Practise each Class A test on its own page: General Knowledge, Air Brakes and Combination Vehicles, each with a free drill.

Practise all three permit tests

The free test shows which knowledge test is below 80%. The Pass Pack gives you seven more mocks and four drills for each.

The CDL Pass Pack gives you 8 full mocks on the real clock, 12 drills of 12 questions for the sections that cost you points, and a predictor that turns your mocks into the odds of reaching your target. One payment, no subscription, and your free score stays free.

Prep courses for these tests usually cost $19 to $129. The CDL Pass Pack is US$39 (£29), once.

See the CDL Pass Pack How our questions are built and checked

8
timed mocks: 12
topic drills: 1
score predictor

How do I get a CDL permit?

Apply at your state licensing office with proof of identity and residency and a DOT medical certificate (for most drivers), pass the knowledge tests for the class you want, and you receive a commercial learner's permit.

Hold a regular driver's license and check the age rules: 18 for driving within your state, 21 for driving across state lines or carrying hazardous materials.
Get a DOT medical examination from a certified examiner if you will drive interstate, and bring the certificate or self-certify your type of driving as your state asks.
Pass the knowledge tests for your class and endorsements with at least 80% on each.
Receive your CLP. You may drive a CMV only with a CDL holder of the right class in the passenger seat.
Hold the CLP for at least 14 days before you take the skills test (49 CFR 383.25).

A CLP is valid for a limited period, no more than a year in total including any renewal, so plan your training so the skills test falls inside it.

Do I need training before the CDL skills test?

Yes, for most new drivers. Federal entry-level driver training (ELDT) rules require anyone getting a Class A or B CDL for the first time to complete theory and behind-the-wheel training with a provider on FMCSA's Training Provider Registry before the skills test.

The same applies to upgrading from B to A and to adding the passenger, school bus or hazmat endorsement for the first time. The training provider reports your completion to the registry, and your state checks it before letting you test.

ELDT does not replace the knowledge tests: you still pass them at the licensing office. Many schools want you to arrive with a CLP already in hand, which is why studying for the knowledge tests first saves money: every week you wait for a permit is a week of tuition doing nothing.

What is on the CDL skills test?

Three parts in the vehicle you will drive: a vehicle inspection (often called the pre-trip), basic control skills such as straight-line and offset backing, and a road test in traffic.

Vehicle inspection: walk around and explain what you check and why, including the in-cab check and the air brake check if your vehicle has air brakes.
Basic control skills: backing and maneuvering exercises in a marked area, scored by pull-ups, encroachments and final position.
Road test: turns, intersections, lane changes, railroad crossings, curves, merging and stopping, with the examiner scoring each.

The air brake check on the skills test uses the same numbers as the Air Brakes knowledge test: the leakage limits, the low-air warning before 60 psi and the spring brakes between 20 and 45 psi. Learning them properly for the written test pays twice.

How do I prepare for the CDL knowledge tests?

Read your state CDL manual sections for the tests you need, take a full practice test to find the weakest test, drill that test with explained answers, and learn the numbers list cold.

General Knowledge is sections 1 to 3 of most manuals, Air Brakes is section 5 and Combination Vehicles is section 6. Read each section once, then switch to questions: answering and checking teaches the rules faster than rereading.

A seven-day plan, with what to read and what to drill each day, is in how to pass the CDL test. The free CDL practice test scores each test against 80% so you know where you stand.

Frequently asked questions

How hard is the CDL test?

The knowledge tests are not hard if you have read the manual, but the 80% line on each test leaves little room: four misses on Combination Vehicles (20 questions) is a fail.

How long does it take to get a CDL?

At least 14 days with a permit before the skills test, plus the time for entry-level training. Full-time training programs commonly take a few weeks.

Can I take the CDL test online?

Some states let you take parts of the knowledge testing online or at third-party sites; most still test at the licensing office. Check your state.

What happens if I fail a knowledge test?

You retest only the test you failed. States set the waiting period and fee, so check your state before you go.

Do I need a medical card for the permit?

Most applicants self-certify their type of driving, and drivers who will drive interstate need a valid DOT medical certificate. Your state tells you which applies.

Who makes the CDL test?

Your state licensing agency gives it, under federal rules from FMCSA. LifeScore is not affiliated with FMCSA or any state agency.

Get your permit on the first visit

Eight full CDL-style mocks, four drills for each knowledge test and every answer explained, for one payment.