Texas CDL Restriction Codes: Equipment, Medical, and Removal

The Texas CDL restriction codes printed on the front of your license each remove some slice of driving authority: a specific transmission, a specific brake system, a specific coupling, a specific class of passenger vehicle, or the right to cross state lines. Which codes you carry depends on the vehicle you took your skills test in and on your medical status. Most can be removed, but the path differs by code.

Where the Codes Come From

Federal regulation defines a core set of restriction letters — E, K, L, M, N, O, V, and Z — and requires every state to apply them the same way.¹ Texas layers additional codes on top of that federal set, covering things like corrective lenses, power steering, weight ceilings, and specialized intrastate categories.² Every code prints on the face of the card, visible to any officer or employer who looks at it.

Equipment Restrictions From Your Skills Test

The vehicle you use on test day sets the ceiling for what you can legally drive afterward. Four codes come directly from that vehicle.

Code E — No Manual Transmission

Test in a truck with an automatic gearbox and you get Code E, which bars you from driving any commercial vehicle with a manual transmission.¹ Many training programs now use automatics because the fleet has shifted that way, but plenty of carriers still run manuals. Removing Code E means passing the skills test again in a manual-equipped vehicle.²

Code L — No Air Brakes

Code L is the broader of the two brake restrictions. You get it by failing the air brake knowledge test or by testing in a vehicle with no air brakes at all. It prohibits you from operating any commercial vehicle with air brakes of any type.³ Because most heavy trucks and buses use air brakes, Code L narrows your options sharply.

Code Z — No Full Air Brakes

Code Z is narrower. It shows up when your skills test vehicle has air-over-hydraulic brakes rather than a full air system. You cannot drive vehicles running entirely on air brakes, but air-over-hydraulic setups remain available to you.³ The distinction matters: L locks out all air brakes, Z locks out only full air.

Code O — No Tractor-Trailer

Code O blocks you from operating any tractor-trailer combination that uses a fifth-wheel connection. It appears when your skills test used a pintle hook or other non-fifth-wheel coupling. For a Class A driver, this is a serious limit, since the standard semi that dominates long-haul freight runs on a fifth wheel.¹ Removal requires retesting in a fifth-wheel combination.

Passenger Vehicle Restrictions

Two codes limit which passenger CMVs you can drive. Both are separate from the P endorsement, which is a separate authorization you must earn by testing before carrying passengers at all.

Code M restricts you from operating Class A passenger vehicles. Class B and Class C passenger vehicles remain open with the P endorsement.²
Code N restricts you from operating both Class A and Class B passenger vehicles, leaving only Class C.¹

Both reflect what you actually demonstrated. Passing your passenger skills test in a smaller bus does not prove you can handle a larger one, and the restriction fills that gap.

Geographic and Medical Codes

Code K — Intrastate Only

Code K is one of the most common restrictions in Texas. It means you cannot cross state lines in a commercial vehicle. Two things put it on your license: being under 21, or not meeting the stricter federal medical standards required for interstate commerce. Federal law requires interstate CMV operators to be at least 21.¹ Texas issues CDLs to drivers as young as 18, but those drivers stay locked into intrastate operations, cannot haul placarded hazardous materials, and cannot pull doubles or triples.

For an under-21 driver, Code K lifts once you turn 21 and update your medical self-certification to an interstate category. For a driver of any age whose medical condition put the code on the license, removal requires a medical examiner’s certification that you meet the full federal physical qualification standards.

Code V — Medical Variance

Code V signals that you hold a federal medical waiver or exemption for a condition that would otherwise disqualify you, such as a vision, hearing, diabetes, or limb condition.¹ The variance lets you drive commercially despite the condition, and the V code tells law enforcement and employers that you are operating under an approved exemption. Keep the underlying variance current; if it lapses, your authority to drive can be affected.

Texas-Added Codes You May See

Beyond the federal letters, Texas prints its own codes on both commercial and non-commercial licenses. The ones CDL holders run into most often:²

Code A: corrective lenses required while driving.
Code H: vehicle not to exceed 26,000 pounds GVWR.
Code W: power steering required.
Code X: no cargo in CMV tank vehicles. This is separate from the N tank endorsement. Code X means you can drive a tank vehicle but cannot haul cargo in the tank.
Code P12: passenger CMVs restricted to Class C only.

Texas also uses a P-series running from P16 through P30 for drivers in excepted interstate commerce categories, including school bus operators, government drivers, fire and rescue personnel, and custom harvesters. Each code identifies the specific federal exemption the driver operates under.

Medical Self-Certification Sits Alongside Your Codes

Every Texas CDL holder has to self-certify into one of four federal categories. This is separate from any letter code on your license, and getting it wrong can trigger a downgrade of your CDL. Texas DPS records your choice on the Self-Certification Affidavit (Form CDL-7).⁴

Non-Excepted Interstate (NI): you drive across state lines and must keep a current federal Medical Examiner’s Certificate (Form MCSA-5876) on file with DPS.⁵
Excepted Interstate (EI): you drive across state lines but fall into a specific exemption, such as school bus drivers, government employees, emergency vehicle operators, and certain agricultural or private transport operations. No federal medical certificate required.
Non-Excepted Intrastate (NA): you drive only within Texas and must meet state medical qualification requirements, including a medical certificate.
Excepted Intrastate (EA): you drive only within Texas and fall into a specific exemption, such as drivers who have held a CDL continuously since 1989, oil and water well service operators, mobile crane operators, and concrete pump operators.

If you run in both interstate and intrastate commerce, you must select the interstate category. If you run in both excepted and non-excepted commerce, you must select non-excepted. The stricter classification always wins.⁴

How to Remove a Restriction

The removal path depends on the type of restriction. Equipment codes (E, L, Z, O) come off through a new skills test. Geographic and medical codes (K, V) come off through updated documentation or a change in eligibility.

Equipment Codes

Schedule a skills test at a Texas DPS CDL testing location and bring a vehicle that lacks the limitation you want removed: a manual transmission truck for Code E, a full air brake vehicle for Code Z, a fifth-wheel combination for Code O. Bring a completed CDL-1 application.⁶ After you pass, DPS charges $11 for a replacement license reflecting your updated status.⁷

Code K

Removing Code K usually means either turning 21 or obtaining medical certification that meets the full federal interstate standard. You need a current Medical Examiner’s Certificate (Form MCSA-5876) from a provider listed on the National Registry of Certified Medical Examiners.⁵ Then update your self-certification category with DPS from intrastate to interstate.

Code V

Code V does not come off through a skills test. It requires the underlying medical variance to be resolved or updated through the federal exemption process.

Military Skills Test Waiver

If you are an active-duty service member or veteran with at least two years of experience operating heavy military vehicles, the FMCSA Military Skills Test Waiver can let you skip the civilian skills test when applying for a CDL, which affects which restrictions land on the license in the first place. You need a commanding officer’s endorsement of your safe driving record, and certain driving violations disqualify you.⁸

Endorsements Are Not Restrictions

The two systems are opposites and easy to confuse. An endorsement adds authority: passenger transport (P), school bus (S), tank vehicles (N), hazardous materials (H), doubles and triples (T), or the combined tank-hazmat (X). A restriction removes authority compared to an unrestricted license of the same class.² You earn endorsements through additional testing, some with a background check. You remove restrictions by retesting in a vehicle that proves you no longer need the limitation, or by updating your medical paperwork.

One quirk worth noting: the letter N appears in both systems. As a restriction on a CDL, N limits your passenger vehicle operations to Class C. As an endorsement, N authorizes you to drive tank vehicles. The code’s meaning depends on which section of the license it prints under, so read the card carefully.

1
eCFR. 49 CFR 383.153 – Information on the CLP and CDL Documents and Card
2
Department of Public Safety. Driver License Endorsements and Restrictions
3
eCFR. 49 CFR 383.95 – Restrictions
4
Department of Public Safety. New Medical Certification Requirements – A Guide for Commercial Drivers
5
FMCSA. Medical Examiner’s Certificate (MEC), Form MCSA-5876
6
Department of Public Safety. How Do I Apply for a Commercial Driver License?
7
Department of Public Safety. Driver License Fees
8
Federal Motor Carrier Safety Administration. Military Skills Test Waiver Program