What CDL restrictions mean and who enforces them

A CDL restriction is a limitation on what you can legally drive or haul with your commercial driver's license. Restrictions are printed on your license itself — usually as a code in a box labeled "Restrictions" — and they are enforced by state motor vehicle departments, the Federal Motor Carrier Safety Administration (FMCSA), and law enforcement during traffic stops or roadside inspections.

Unlike an endorsement, which adds something you are allowed to do, a restriction removes something you would otherwise be allowed to do. If your license shows a restriction, you cannot legally operate a vehicle or transport cargo that falls outside that restriction without first removing it through testing or documentation. Violating a restriction can result in fines, out-of-service orders, and points on your driving record.

The most common restrictions affect the type of vehicle you can drive (automatic transmission only, for example), the cargo you can haul (no hazmat), or the passengers you can carry (no passengers in certain vehicle classes). Some restrictions are temporary — tied to a medical condition or a recent violation — while others are permanent unless you take action to remove them.

Key Takeaways

  • Restrictions are codes printed on your CDL that limit what vehicle types, cargo, or passengers you can legally operate with your license.
  • Common restrictions include automatic transmission only, no hazmat, no passengers, and air brake restrictions, each with different removal paths.
  • Medical restrictions (vision, hearing, diabetes management) can be temporary or permanent depending on whether you meet FMCSA standards and obtain required documentation.
  • Removing a restriction usually requires passing a skills test, obtaining a medical certificate, or submitting proof of training — the exact requirement depends on the restriction code.
  • Driving outside your restrictions is a violation that can result in fines, out-of-service orders, and a mark on your record that affects future employment.

The most common CDL restrictions and what they prohibit

The FMCSA and state motor vehicle departments use standardized restriction codes. The ones you encounter most often are:

Automatic transmission only (code L) means you cannot operate a vehicle with a manual transmission. This restriction is typically imposed if you took your CDL skills test in an automatic transmission truck. To remove it, you must pass the skills test again in a manual transmission vehicle.

No hazardous materials (code H) means you cannot transport any cargo classified as hazardous under Department of Transportation rules — explosives, flammable liquids, gases, poisons, radioactive materials, and others. This restriction is common for drivers who did not pass the hazmat endorsement test or who failed a background check required for hazmat transport. Removing it requires passing the hazmat knowledge test and passing a background check through the Transportation Security Administration (TSA).

No passengers (code N) means you cannot transport passengers for hire in a Class B or Class C vehicle. This restriction applies to drivers who did not pass the passenger endorsement test or who are not medically cleared for passenger transport. Removing it requires passing the passenger endorsement knowledge and skills tests.

Air brake restriction (code Z) means you cannot operate any vehicle equipped with air brakes — which includes most heavy trucks and many buses. This restriction is imposed if you took your skills test in a vehicle with hydraulic brakes only. To remove it, you must pass the air brake knowledge test and the skills test in a vehicle with air brakes.

Medical restrictions and how they are imposed and removed

The FMCSA maintains medical standards for CDL drivers. If you do not meet those standards, your state will impose a medical restriction on your license. These restrictions are tied to specific health conditions and are enforced through the Medical Examiner's Certificate (MEC) — a document you must carry while driving and renew every two years (or one year if you have certain conditions).

Common medical restrictions include vision restrictions (if your vision does not meet the 20/40 standard in each eye), hearing restrictions (if you cannot hear a forced whisper at three feet), and insulin-use restrictions (if you manage diabetes with insulin). Some states also impose restrictions for drivers with sleep apnea, cardiovascular conditions, or neurological disorders that do not fully meet FMCSA standards but warrant monitoring.

To remove a medical restriction, you must obtain a new Medical Examiner's Certificate from an FMCSA-certified medical examiner showing that you now meet the standard for that condition. For vision restrictions, this usually means obtaining corrective lenses that bring your vision to 20/40 or better. For insulin-use restrictions, you must provide documentation that your diabetes is well-controlled and that you have a plan for managing it while driving. The medical examiner will note on your certificate whether the restriction can be removed, and you then take that certificate to your state motor vehicle department to update your license.

Restrictions imposed for violations or failed tests

If you fail the CDL knowledge or skills test, your state will impose restrictions on your license based on what you failed. For example, if you fail the air brake component of the skills test, you will receive an air brake restriction. If you fail the hazmat knowledge test, you will not be issued a hazmat endorsement, and you may receive a no-hazmat restriction if your employer requires it.

Some states also impose temporary restrictions after certain violations. If you are convicted of a moving violation while driving a commercial vehicle, or if you receive an out-of-service order for a safety violation, your state may restrict your license for a set period — usually 30 to 90 days — until you complete a remedial training course or pass a re-examination.

Removing a violation-based restriction requires either waiting out the restriction period and then passing a re-test, or in some cases completing a state-approved training program and then passing a re-test. The exact path depends on your state's rules and the nature of the violation.

How to find out what restrictions are on your license

Your CDL restrictions are printed on the front or back of your physical license card, usually in a box labeled "Restrictions" or "Codes." The restrictions are shown as letter codes — L, H, N, Z, and others — each corresponding to a specific limitation.

If you cannot read the codes clearly or want a detailed explanation of what each one means, you can contact your state's motor vehicle department and ask for a printout of your driving record. The record will list your restrictions in plain language. You can also ask your employer or your CDL training school to explain what each code means and what you need to do to remove it.

Some states also allow you to view your driving record online through their motor vehicle department website. If your state offers this service, you can log in with your license number and date of birth to see your restrictions and any notes about when they were imposed or when they expire.

The cost and timeline for removing restrictions

The cost of removing a restriction varies by state and by the type of restriction. A skills test retake typically costs between $100 and $300, depending on your state and whether you use a third-party testing facility. A knowledge test retake usually costs $10 to $50. Medical examinations required to remove medical restrictions can cost $50 to $150, depending on the complexity of your condition and whether your insurance covers it.

The timeline also varies. If you are removing a restriction by retaking a test, you can usually schedule the test within one to four weeks. If you are removing a medical restriction, you may need to wait until your condition improves or until you have obtained the necessary medical documentation — this can take anywhere from a few weeks to several months. Once you pass a test or obtain the required documentation, your state typically updates your license within one to two weeks.

Some restrictions cannot be removed — for example, if you are permanently disqualified from holding a CDL due to a serious violation, your state will not remove that restriction. In those cases, you would need to wait out the disqualification period (which can be one to ten years, depending on the violation) and then reapply for a CDL from scratch.

What happens if you drive outside your restrictions

Driving a vehicle or hauling cargo that violates your CDL restrictions is a federal violation under FMCSA rules. If you are stopped by law enforcement or inspected at a weigh station, an officer can issue you a citation, fine you, and place you out of service — meaning you cannot legally operate a commercial vehicle until the violation is resolved.

The fine for a restriction violation typically ranges from $100 to $500, depending on your state and the severity of the violation. More importantly, the violation will be recorded on your driving record and reported to the FMCSA's Safety Management System, which is used by insurers and employers to assess your safety record. A restriction violation can make you uninsurable or unemployable in the commercial driving industry.

If you repeatedly violate your restrictions, you may face license suspension or revocation. Some states also allow employers to terminate you for operating outside your restrictions, and some insurance policies include clauses that deny coverage if you cause an accident while violating a restriction.

Frequently Asked Questions

Can I remove an automatic transmission restriction by taking a test in a manual truck?

Yes. You must pass both the knowledge test and the skills test in a manual transmission vehicle. The skills test must be administered by an approved testing facility in your state. Once you pass, your state will remove the restriction from your license, usually within one to two weeks.

What if I have a medical condition that causes a restriction — can I still drive?

Yes, as long as you carry a valid Medical Examiner's Certificate and follow any conditions listed on it. Some medical restrictions allow you to drive with certain limitations (for example, daylight hours only or within a certain distance of home). Your medical examiner will specify what you can and cannot do. If your condition worsens, you must notify your state motor vehicle department.

How long does an air brake restriction stay on my license?

An air brake restriction stays on your license until you pass the air brake knowledge test and the skills test in a vehicle with air brakes. There is no time limit — you can remove it whenever you are ready to take the test. However, if you are required to operate air brake vehicles for your job, you will need to remove the restriction before you can legally do so.

Will a restriction violation affect my insurance rates?

Yes. A restriction violation is reported to the FMCSA Safety Management System and will appear on your driving record. Insurance companies use this record to calculate your rates, and a violation will likely increase your premiums or cause your insurer to drop you. Some insurers will not cover you at all if you have a recent restriction violation.

Can I drive a vehicle with an automatic transmission if I have an automatic-only restriction?

Yes. An automatic-only restriction means you can only drive automatic transmission vehicles — you cannot drive manual transmission vehicles. If your restriction is automatic-only, you are legally allowed to operate any automatic transmission commercial vehicle that you are otherwise licensed to drive.