Missouri’s Commercial Driver’s License Laws

The requirements to obtain a Missouri CDL and the reasons for disqualification.

Like all states, Missouri requires commercial motor vehicle (CMV) operators to possess a commercial driver's license (CDL). Missouri has special rules regarding the type of license a commercial operator must have and the requirements for obtaining a CDL. Missouri also has strict penalties for drivers who fail to comply with CDL rules. This article outlines the types of CDLs, the application process, and how a CDL can be disqualified.

When a CDL is Required

Missouri requires a CDL for all vehicles defined as CMVs. This definition includes any vehicle weighing 26,001 or more pounds or designed to carry hazardous materials or 16 or more passengers. A farm vehicle operated by a farmer to transport agriculture products within 150 miles of the farm is not considered a CMV.

Missouri's CDL License Categories

There are three classes of CDLs corresponding to the weight of the truck and/or trailer(s).

Combined Weight

Tractor Weight

Trailer(s) Weight

Class A

26,001 or more pounds

26,001 or more pounds

Over 10,000 pounds

Class B

26,001 or more pounds

26,001 or more pounds

Not over 10,000 pounds

Class C

Less than 26,001 pounds

Less than 26,001 pounds

Not over 10,000 pounds

A higher-grade CDL can always be used to operate a lower-class CMV. In other words, a class A CDL holder can operate all weights of CMVs.

Cargo Endorsements

Endorsements can be added to the driver's CDL to haul special cargo but require additional testing and education. For example, an "H" endorsement authorizes hazardous material transportation but the driver must be at least 21 years old and have TSA clearance.


A CDL can also include certain restrictions based on the driver's age or health. For example, drivers under 21 years old are limited to only in-state operation.

CDL Testing

All CDL applicants must first obtain a commercial driver's instruction permit (CDIP). A CDIP requires the applicant to be at least 18 years old, show proof of residency, and pass the written exam. The CDIP can be used to operate a CMV but only under the supervision of a licensed commercial driver. After 14 days of practice, the CDIP-holder can take a driving test to obtain a full CDL.

Transparency. A CDL also requires a driving record check for any serious or prohibitive convictions. Even after issuance, a CDL holder is required to disclose all future traffic convictions and license penalties to the state and to employers.

Medical exam. CDL holders are required to submit to a medical examination to ensure adequate physical fitness to operate a CMV. Certain medical conditions may result in license restriction or disqualification. Failure to maintain an annual medical card will result in CDL license revocation.

CDL Revocation and Disqualification

A Missouri CDL can be revoked for CMV regulation violations and certain criminal convictions.

Serious traffic violations. "Serious traffic violations" include speeding 15 miles per hour or more over the limit, reckless driving, texting while driving, and any traffic violation involving a fatality. Erratic lane change and following too closely are only considered serious traffic violations if they occur in a CMV. The driver's license will be disqualified for at least 60 days for having two serious traffic violations in three years and at least 120 days for having three or more violations in three years. Driving without a CDL, without a CDL in possession, and without proper endorsements are serious traffic violations and class A misdemeanors. A driver can avoid a conviction for driving without a CDL by presenting a then-valid CDL later in court.

Out-of-service order. Certain safety violations can result in the issuance of an immediate, but temporary, out-of-service order (OSO). Driving in violation of an OSO is a class A misdemeanor and will result in the driver being revoked for 180 days to one year for a first offense, two to five years for a second offense, and three years for a third or subsequent offense. If the operated vehicle was designed to carry hazmat or 16 or more passengers, the license will be disqualified 180 days for a first offense and three years for a second or subsequent offense. The driver, and even the employer, might also face civil penalties.

Railroad crossings. Missouri has special rules for operating a CMV near or over railroad tracks. CMV operators must stop or slow down for all crossings and must ensure the CMV has enough clearance in front and below to safely cross. Railroad track violations will result in a minimum 60-day, 120-day, and one-year license disqualification for a first, second, and third violation in three years.

Convictions. Certain serious traffic convictions will result in a minimum one-year CDL revocation. This list includes chemical test refusal, DWI (driving while intoxicated), leaving the scene of an accident, using a motor vehicle in the commission of a felony, driving a CMV while revoked, and causing a fatality due to negligent CMV operation. Any of these violations committed while transporting hazardous materials will result in a minimum three-year disqualification. A second or subsequent conviction will result in lifetime disqualification but reinstatement is possible after ten years. Any conviction involving the use of a motor vehicle to distribute or transport controlled substances will result in permanent lifetime disqualification.

Implied consent. All CMV operators are deemed to have impliedly consented to a test of their breath, blood, or urine to determine the presence of drugs or alcohol. An officer who has probable cause to believe the driver has alcohol or drugs in his or her system can request chemical testing. Refusal to submit to the test will result in license disqualification, a 24-hour OSO order, and possible criminal penalties.

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