Missouri CDL practice tests

Missouri handles commercial licensing through its Department of Revenue, which is an unusual home for it — most people expect licensing to sit with a transport or public safety agency, not the tax authority. If you have only dealt with Revenue for vehicle titling before, know that your CDL paperwork goes through the same department.

What Missouri requires

Every figure below names the document it came from, so you can check it rather than take our word for it.

Passing score
80% 49 CFR Part 383, Commercial Driver's License Standards, 383.135
Minimum age (in-state driving)
18 years old 49 CFR Part 383, Commercial Driver's License Standards, 383.71
Minimum age (across state lines)
21 years old 49 CFR Part 391, Qualifications of Drivers, 391.11
Permit holding period
14 days 49 CFR Part 383, Commercial Driver's License Standards, 383.25

Fees change without notice, so we do not repeat them here. Check Missouri Department of Revenue for the current cost.

Missouri practice tests

The knowledge tests are set by federal rule, so the questions are the same wherever you sit them. What changes is the paperwork above.

A crossroads state

Missouri sits where several major interstates meet — I-70 running east-west and I-44 and I-35 cutting through it as well — which makes it a genuine hub for long-haul trucking rather than somewhere drivers only pass through occasionally. That is not a reason to expect an easier test; it just means the state has more day-to-day reason than most to keep its licensing process working smoothly for commercial drivers.

The exam content is set federally

Whatever agency administers it, the knowledge test itself comes from 49 CFR Part 383. General knowledge, air brakes, combination vehicles, hazardous materials — all federally defined, so studying for a Missouri exam prepares you for the same material as any other state's. The 80 percent pass mark per section is likewise federal, not a Department of Revenue policy.

Matching tests to your vehicle

Everyone takes general knowledge. After that, what you need depends on what you drive: air brakes on the vehicle means sitting the air brakes exam, and not sitting it does not block licensing outright — it puts a restriction on the license barring air-brake-equipped vehicles instead. A trailer over ten thousand pounds pulls in combination vehicles. Endorsements — tank, doubles and triples, passenger, school bus, hazardous materials — are added on top only for drivers who need them.

Hazardous materials brings an extra requirement beyond the written exam: a Transportation Security Administration background check. It runs on a federal timeline that has nothing to do with your knowledge test score, so it pays to start it early rather than leaving it until the rest of your application is ready.

Planning around the permit

A commercial learner permit must be held at least 14 days before the skills test, under federal rule. Use that period well: sit your knowledge exams near the start of it so a re-sit, if you need one, does not push into time you need for the skills test. Age rules are federal too — 18 is enough to drive commercially inside Missouri, but 21 is required the moment the route crosses into another state, which matters more here given how much through-traffic runs across state lines.

No fees published here

We don't list dollar amounts on this site. The Department of Revenue sets and changes them, and a number we publish today could be wrong by the time you read it — a stale fee sends someone to the counter expecting the wrong total. Check the current fee with the Department of Revenue directly. What we reliably provide is exam scope and a named source behind every answer.

Jump to a test

Every question on every one of these is free, and each answer names the handbook page it came from.

Other states

Cited to the page, every time.

Every question names the handbook, section and page it was read from, so you can check the answer instead of taking our word for it.

How we write these