Missouri CDL practice tests
Missouri splits the job between two agencies, the Department of Revenue issues the license while the Highway Patrol runs the exam stations, and it stamps every learner permit with a hard 360 day, non-renewable clock rather than the flat one year term most states use.
The written exams themselves are federal. Missouri decides the permit rules, the fees and who runs the skills test, but the knowledge you are tested on comes from 49 CFR Part 383 and is the same in every state, which is why the 145 questions here work wherever you apply.
What changes in this state
Commercial learner permit
Missouri requires an applicant to hold the commercial learner permit for a minimum of 14 days before completing skills testing, and the permit is issued for 360 days and cannot be renewed.
Missouri Department of Revenue, CDL Permit Rule Overview, checked 2026-08-28
Fees
A commercial learner permit costs $44, made up of a $25 written exam fee, a $10 permit transaction fee, and a $9 office processing fee.
Missouri Department of Revenue, Commercial Drivers, checked 2026-08-28
Where you test
Knowledge testing is offered at any Missouri State Highway Patrol Driver Examination Station, while skills testing runs by appointment only at designated Highway Patrol CDL test sites or through certified third party testers.
Missouri Department of Revenue, Commercial Drivers, checked 2026-08-28
Every knowledge area
General Knowledge
Required of every applicant: inspection, control, space and speed management, hazard perception, emergencies and hours of service.
Air Brakes
Fail this and an L restriction bars you from any vehicle with air brakes, which is most of them.
Combination Vehicles
Coupling, the fifth wheel, off tracking and trailer swing. Needed for Class A.
Hazardous Materials
Placards, shipping papers, segregation and the security threat assessment.
Tank Vehicles
Liquid surge, baffles, outage and why a tanker rolls over so readily.
Doubles and Triples
Rearward amplification, converter dollies and coupling a second or third trailer.
Passenger Transport
Bus inspection, standee lines, passenger supervision and railroad crossings.
School Bus
Danger zones, loading and unloading, student crossing and evacuation.