What you need to know before you start

A Commercial Driver's License (CDL) in Missouri is issued by the Missouri Department of Revenue and lets you operate trucks, buses, and other large vehicles for pay. You cannot straightforward upgrade an existing license — you must pass a written knowledge test, a skills test, and a medical exam, and you must be at least 18 years old (21 if you want to drive across state lines). The whole process typically takes several weeks from start to finish.

Missouri recognizes three classes of CDL based on vehicle weight and cargo type: Class A (combination vehicles over 26,001 pounds), Class B (single vehicles over 26,001 pounds), and Class C (smaller vehicles carrying hazardous materials or 16 or more passengers). You will also need to decide whether you want any endorsements — the additional qualifications that let you haul specific cargo like hazmat or tanker loads.

Key Takeaways

  • You must hold a valid Missouri driver's license, pass a medical exam, and be at least 18 years old to begin the CDL process.
  • The written test covers general knowledge, air brakes, and combination vehicles (depending on the class you want), and you can study using the official Missouri CDL manual.
  • The skills test includes a pre-trip vehicle inspection, a backing maneuver, and an on-road driving portion, and you must pass all three parts in one day.
  • Missouri allows you to take the written test at any Missouri Department of Revenue office, but the skills test must be taken at an approved testing facility or through a certified CDL training school.
  • Endorsements like hazmat or tanker require separate written tests and may require additional background checks or fingerprinting.

Starting the process: what documents you need

Before you walk into a Department of Revenue office, gather your current Missouri driver's license, proof of Social Security number (your Social Security card, W-2, or 1099), and proof of Missouri residency (a utility bill, lease, or mortgage statement dated within the last 60 days). You will also need to complete the Medical Examination Report (MCSA-5875) with a certified medical examiner — this is not your regular doctor's visit, but a specific federal exam that checks your vision, hearing, blood pressure, and ability to operate a commercial vehicle safely.

The medical exam costs money out of your pocket (typically $50 to $150, depending on the examiner), and you must pass it before you can take the written test. Find a certified medical examiner through the Federal Motor Carrier Safety Administration (FMCSA) website, which lists all approved examiners in Missouri by county. Once you have the completed form, bring it with you when you explore.

Taking the written knowledge test

The written test is broken into sections depending on which class of CDL you want. All applicants take the General Knowledge test (50 questions, 80% passing score). If you are testing for Class A or B, you also take the Combination Vehicles test (20 questions). If your vehicle has air brakes, you must pass the Air Brakes test (25 questions). Hazmat endorsements, tanker endorsements, and passenger endorsements each have their own separate written tests.

You can study using the free Missouri CDL Manual, available as a PDF on the Missouri Department of Revenue website. The manual covers vehicle inspection, safe driving practices, cargo handling, and the specific rules for each endorsement. Many people also use third-party study apps or take a CDL training course, though neither is required by Missouri law. You can take the written test at any Missouri Department of Revenue office during regular business hours — no appointment needed, though wait times vary by location.

Scheduling and passing the skills test

Once you pass the written test, you are cleared to take the skills test, which has three parts: the pre-trip inspection (you walk around the vehicle and point out safety features and check for damage), the backing maneuver (you reverse the vehicle into a tight space), and the on-road driving test (you drive the vehicle on public roads while an examiner watches). All three parts must be completed on the same day, and you must pass all three to pass the skills test.

The skills test must be taken at an approved testing facility or through a certified CDL training school. Missouri does not allow you to take the skills test at a Department of Revenue office — you must go to a third-party tester. You can find approved testing facilities on the Missouri Department of Revenue website. If you attend a CDL training school, many schools offer both the written and skills tests on-site, which can speed up the process. Training schools typically cost $1,000 to $3,000 and take one to four weeks, depending on the program.

Adding endorsements to your CDL

Once you have your CDL, you can add endorsements by passing additional written tests at any Missouri Department of Revenue office. The most common endorsements are Hazmat (hazardous materials), Tanker (tank vehicles), Passenger (buses or vans with 16 or more seats), and Double/Triple (multiple trailers). Each endorsement test is 20 to 30 questions and covers the specific rules and safety practices for that cargo or vehicle type.

Hazmat endorsements require a background check and fingerprinting through the Transportation Security Administration (TSA), which adds time and cost. You will need to visit a TSA-approved fingerprinting location (usually a local police department or private fingerprinting service) and pay a fee. The TSA then reviews your background, which can take several weeks. Other endorsements do not require background checks and can be added when ready after you pass the written test.

Renewing and maintaining your CDL

Your Missouri CDL is valid for eight years from the date it is issued. You must renew it before it expires by visiting a Missouri Department of Revenue office with your current license, proof of residency, and a new medical examination report. You do not have to retake the written or skills tests to renew — only the medical exam is required. If your CDL expires, you will have to retake all tests to get a new one.

You must also report any traffic violations, accidents, or disqualifying offenses to the Department of Revenue within 30 days. Certain violations (like driving under the influence, reckless driving, or leaving the scene of an accident) can result in CDL suspension or revocation, even if they happen in a personal vehicle. Keeping your record clean is essential to keeping your CDL active.

Frequently Asked Questions

Can I get a CDL if I have a suspended or revoked driver's license?

No. You must have a valid, unrestricted Missouri driver's license before you can get a CDL. If your license is suspended or revoked, you must resolve that issue first and restore your driving privileges.

What happens if I fail the skills test?

You can retake the skills test at the same testing facility. There is no waiting period between attempts in Missouri, though you may have to pay the testing fee again. Most people pass on the second or third try after practicing with a trainer or school.

Do I need to take a CDL training school or can I study on my own?

Missouri does not require formal training — you can study the manual on your own and take the tests independently. However, many people find that hands-on training with a professional instructor makes passing the skills test easier, especially the backing maneuver and pre-trip inspection.

How long does the whole process take?

If you study on your own and use a third-party testing facility, the process typically takes three to six weeks from the medical exam to receiving your CDL. If you attend a training school, it can take one to four weeks depending on the program length, since schools often offer testing on-site.

Can I drive a commercial vehicle while my CDL process is pending?

No. You cannot legally operate a commercial vehicle for pay until your CDL is issued and in your hand. Driving without a valid CDL is a serious violation and can result in fines and criminal charges.