Missouri CDL Study Guide
Missouri issues commercial driver licenses through the Department of Revenue Driver License Bureau, with skills testing run by the Missouri State Highway Patrol. The state follows federal CDL rules in its Commercial Driver License Manual. You can drive a commercial vehicle inside Missouri at 18. You must be 21 to drive across state lines or carry hazardous materials.
Key Missouri numbers
- Minimum age (intrastate): 18
- Minimum age (interstate or hazmat): 21
- CLP hold before skills test: at least 14 days
- General Knowledge passing score: 80%
- General Knowledge test: ~50 questions
- Air Brakes test: ~25 questions (required if your vehicle has air brakes)
- Combination Vehicles test: ~20 questions (required for Class A)
Topics on the Missouri General Knowledge test
- Vehicle inspection (pre-trip, en-route, post-trip)
- Driving safely (speed management, space management, hazard perception)
- Transporting cargo safely
- Air brakes (if your vehicle is air-braked)
- Combination vehicles (Class A)
If you fail a test
If you fail a CDL knowledge or skills test in Missouri, you may schedule a retake. Additional fees may apply. See the Missouri Department of Revenue Commercial Drivers page for current retake details.
Frequently asked questions
How old do I need to be to get a CDL in Missouri?
You must be at least 18 to drive a commercial vehicle inside Missouri. You must be 21 to drive across state lines or carry hazardous materials.
How long must I hold my Missouri CLP before the skills test?
You must hold your Commercial Learneru0027s Permit for at least 14 days before you can take the CDL skills test.
How much does a Missouri CDL cost?
Most first-time applicants pay about $83: a $40 license fee, $18 office processing fee, and $25 skills test fee.
Do I need to take Entry-Level Driver Training in Missouri?
Yes. If you are getting your first Class A or B CDL, or your first H, P, or S endorsement, you must complete federal ELDT from an FMCSA-registered provider.
Do I need a DOT medical card to get a Missouri CDL?
Yes. You must complete a DOT medical exam and submit your Medical Examineru0027s Certificate to the Department of Revenue.
What is the official Missouri CDL manual?
The Missouri Commercial Driver License Manual is the official study guide. You can download it free from dor.mo.gov.
Free practice
Start a Missouri General Knowledge quiz →
Sources: Missouri CDL Manual (PDF) Missouri Department of Revenue Commercial Drivers page Missouri Department of Revenue Fee Chart (PDF) Missouri Driver Guide