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CDL Endorsements & Restrictions

Before earning your commercial driver’s license, you’ll first want to figure out which type of vehicle you want to drive using your CDL. Hoping to drive a tanker truck, or maybe haul hazardous materials? Or perhaps you’d love to carry passengers, like on a city bus or even a school bus? Regardless of what you choose, you’ll need the proper CDL endorsement to do so!

On the flip side, if you’re unable to prove certain skills during your CDL exams, you may also have restrictions placed on your license. Though these can be removed, it’s always better to understand ahead of time what might cause a restriction so you can prevent it in the first place.

Here’s a breakdown of the CDL endorsements and restrictions you need to know.

CDL Endorsements

What Are CDL Endorsements?

Commercial driver license endorsements are additional credentials that authorize a CDL holder to drive specific types of commercial vehicles. While some commercial vehicles are covered by your standard Class A or B driver’s license, many require additional knowledge and skills to safely operate them. Driving a school bus is much different than driving a triple-trailer semi-truck; as such, you’ll need to know the specific safety regulations, traffic rules, and maneuvering operations that apply to the vehicle you’ll be driving.

Some endorsements go hand-in-hand with specific CDL classifications; for example, a Class C CDL allows the driver to transport passengers or hazardous materials, both of which also require you to earn the respective CDL endorsement (either a P or S endorsement for passengers, or an H endorsement for HAZMAT).

List of CDL Endorsements

The Federal Motor Carrier Safety Administration (FMCSA) designates six different endorsements that you can add to your commercial driver’s license.

  • “N” endorsement: This tanker endorsement allows you to carry liquid cargo in tanker trucks.
  • “T” endorsement: This authorizes you to drive double and/or triple trailers.
  • “P” endorsement: “P” stands for “passenger”; this endorsement allows you to drive a vehicle built to carry at least 16 people (including yourself as the driver).
  • “S” endorsement: This is a school bus endorsement—you must first earn a “P” passenger endorsement before you can move up to driving school buses and looking after children.
  • “H” endorsement: This is the hazardous materials (HAZMAT) endorsement that’s required to haul any cargo with the potential to cause bodily or environmental harm. Depending on the HAZMAT you’ll be carrying, you may also need an “X” endorsement (see below). The HAZMAT endorsement is also unique in that it's the only CDL endorsement that requires a background check.
  • “X” endorsement: This combines the “N” tanker and “H” HAZMAT endorsements into a single CDL credential. You’ll need to meet both endorsements’ testing and background check requirements.

Additionally, your specific state DMV agency may offer additional endorsements, including:

  • Air brakes
  • Metal coil
  • Double trailers
  • Firefighter

How to Apply for a CDL Endorsement

You’ll apply for your CDL endorsement(s) when you apply for your commercial learner’s permit (CLP). You can check out our complete breakdown of how to get your CDL and applicable endorsements, but in general, you’ll need to:

  • Undergo a TSA threat assessment (“H” and “X” endorsement applicants only).
  • Take the general knowledge exam for a Class A, B, and/or C commercial driver’s license.
  • Pass the applicable knowledge test(s) for your specific endorsement(s).
  • Hold your CLP for the designated amount of time before taking your skills test.
  • Perform endorsement-specific maneuvers and inspections for your CDL road skills exam.


CDL Restrictions

What Are CDL Restrictions?

Conversely to CDL endorsements, CDL restrictions are codes added to your commercial driver’s license that prohibit you from driving certain types of vehicles. These restrictions can be due to a number of factors—they can be medically related, for example, or because of anomalies while taking your specific endorsement exam (or not taking the required test at all).

List of CDL Restrictions

Here are the FMCSA’s CDL restrictions—your state may have others that it assesses in addition to these.

  • “E” restriction: This code stands for “no manual transmission.” You’ll receive an E restriction if you take your CDL skills test in a vehicle that has an automatic transmission (thereby not proving your operative skills with a manual transmission).
  • “L” restriction: This prevents you from driving a vehicle with an air brakes system. The DMV will assess an L restriction when your license class allows for air brakes but you either:
    • Don’t pass an air brakes knowledge exam
    • Don’t take your CDL road test in a vehicle with an air brake system
    • Fail to correctly identify the air brake system components
    • Fail to properly conduct an air brake systems check
  • “M” restriction: This code is specific to drivers with P passenger or S school bus endorsements, restricting you to driving only Class B or C passenger vehicles or school buses. You’ll receive this code if you hold a Class A CDL, but you tested for your endorsement(s) in a Class B vehicle.
  • “N” restriction: Much like the M restriction but narrower, the N code restricts you to driving only a Class C passenger vehicle or school bus with your P or S endorsement. This happens if you hold a Class B CDL, but you tested for your endorsement(s) in a Class C vehicle.
  • “O” restriction: This code prohibits you from driving any Class A vehicle that has a fifth-wheel connection. You’ll receive an O restriction if you test for your Class A CDL in a vehicle built with a pintle hook or other non-fifth-wheel connection.
  • “V” restriction: This is a medical restriction, assessed when you’ve received a medical variance as part of your DOT medical exam requirements. A V code can indicate a hearing or visual impairment, a seizure condition, diabetes, or other medical condition.
  • “Z” restriction: This restriction prohibits you from driving a vehicle with a full air brake system. You’ll receive this code if you test for your CDL in a vehicle built with an air-over-hydraulic brake system.

How to Remove a CDL Restriction

Removing a CDL restriction will depend on how you got it in the first place. Usually, it’s a matter of re-testing for your CDL and/or endorsement in the proper vehicle type that includes the components you’ve been restricted from operating. For example, if you tested in a vehicle without a full air brake system and received a Z restriction, you’ll need to retake the test in a vehicle that’s fully equipped with air brakes to have that restriction removed. 

If you have a V restriction due to a medical reason, you’ll need to obtain a new DOT medical certificate that doesn’t list the medical variance which earned the restriction. For example, if you had visual impairments but recently had surgery to correct them and now have sufficient eyesight, your medical provider can certify that you’re now medically able to have the V restriction removed. This process will entail visiting your federally authorized medical provider, resubmitting your medical examiner’s certificate to your DMV agency, and repeating the medical self-certification process to update your file.

Regardless of what kind of restriction you want to remove, you’ll very likely need to visit your DMV agency to reapply for a replacement or renewal CDL, including paying the applicable fee for a new credential.