What does restriction L mean on a CDL?

L means no air brake equipped CMV. You may not drive a commercial vehicle with any type of air brakes. Federal rule 49 CFR 383.95(a) says the state adds it if you fail the air brake part of the knowledge test, or take the skills test in a vehicle with no air brakes. Air brakes here include any system that works fully or partly on the air brake principle.

What does the E restriction mean on a CDL, and can I remove it?

E means no manual transmission equipped CMV. The state adds it if you take the skills test in a truck with an automatic transmission. You can remove it. Under 49 CFR 383.135(b)(7) you do not retake the whole skills test, and the state may give a modified test in a manual truck. States list different steps, so check yours.

Do I need entry-level driver training to remove an L, Z or E restriction?

No. FMCSA's Training Provider Registry FAQ says drivers who apply to remove the no air brake (L), no full air brake (Z) or no manual transmission (E) restriction under 49 CFR 383.135(b)(7) are not subject to entry-level driver training. You still have to pass the tests your state requires.

CDL Restriction Codes: What E, L, Z, K and P Mean

CDL restriction codes are one-letter marks on your license that limit which commercial vehicles you may drive. The common ones are E (no manual transmission), L (no air brakes), Z (no full air brake) and O (no tractor-trailer).

Most of them come from the truck you used for your skills test. Test in an automatic truck and you get E. Test in a truck with no air brakes and you get L. Last checked October 21, 2026.

How to read the letters

The federal rule, 49 CFR 383.153, lists the standard restriction letters. The rule says what each letter means in a short phrase. State manuals print the same letters and explain them. We checked the federal text and these state sources: South Carolina, Oregon, Texas, California, New York and the Virginia CDL manual.

All of them agree on the meaning of the letters below. Where a state does something different, we say so.

CDL restriction codes list

Code	What it means	Why you get it	How to remove it	Source
E	No manual transmission equipped CMV	You took the skills test in a truck with an automatic transmission. A semi-automatic counts as automatic.	Pass a skills test in a truck with a manual transmission.	383.95(c), 383.5, SC
L	No air brake equipped CMV	You failed the air brake part of the knowledge test, or you took the skills test in a vehicle with no air brakes.	Pass the air brake knowledge test, the air brake pre-trip inspection and the skills test in a truck with air brakes.	383.95(a), 383.135, Oregon
Z	No full air brake equipped CMV	You took the skills test in a truck with air over hydraulic brakes.	Same as L, but the test truck must have full air brakes.	383.95(b), 383.135, SC
O	No tractor-trailer CMV	You took the Class A skills test in a combination joined by a pintle hook or other non-fifth wheel connection.	Retake all three skills tests in a tractor-trailer with a fifth wheel.	383.95(d), 383.135(b)(8), SC
M	No Class A passenger vehicle	You took the passenger skills test in a vehicle that needs a Group B CDL.	Pass the passenger skills test in a Class A passenger vehicle.	383.95(e), SC
N	No Class A and B passenger vehicle	You took the passenger skills test in a vehicle that needs only a Group C CDL.	Pass the passenger skills test in a Class A or B passenger vehicle. SC says a Class B test swaps N for M.	383.95(f), SC
P	No passengers in CMV bus (permit only)	You hold a CLP with a passenger (P) or school bus (S) endorsement.	Pass any knowledge tests needed and the complete skills test for that bus.	383.153(b), SC
X	No cargo in CMV tank vehicle (permit only)	You hold a CLP with a tank (N) endorsement. You may drive only an empty tank.	Pass any knowledge tests needed and the complete skills test for that vehicle.	383.153(b), SC
K	Intrastate only	Your state limits you to driving inside the state. The reason depends on the state.	Depends on why it was added. South Carolina adds it for ages 18 to 20 and removes it at 21.	383.153, SC, NY
V	Medical variance	FMCSA issued you a medical variance and told your state.	It stays while the variance applies.	383.95(g), SC

The restriction rules in 49 CFR 383.153(g) apply to skills tests taken on or after July 8, 2015. Drivers who already held a CDL were not required to retest for E, Z or O.

What E, L and Z mean in plain words

E. A manual transmission has a clutch you work with a pedal or lever and a gear shift. Under 49 CFR 383.5, every other transmission counts as automatic for this restriction. That includes semi-automatic ones.

L. This is the widest air brake restriction. The rule says air brakes include any system that works fully or partly on the air brake principle. So L keeps you out of air over hydraulic trucks too.

Z. This one is narrower. A full air brake system works fully on the air brake principle. Air over hydraulic means a system that is partly air and partly hydraulic. If you tested in an air over hydraulic truck, you may drive other air over hydraulic trucks, but not full air brake trucks.

Pick your skills-test truck so you don't get E, L or Z

The rule ties the restriction to the truck you test in. So the best fix happens before test day. We tell new drivers to call the school or the testing site and ask three things:

Is the test truck a manual or an automatic?
Does it have full air brakes? Ask them to say "full air" or "air over hydraulic" in plain words.
For Class A, is it a tractor with a fifth wheel pulling a semi-trailer?

One wrong answer here puts a letter on your license. A driver who passes in an automatic gets E, and then has to go back to a testing site later for the modified test if a job needs a manual. We would rather you spend ten minutes on the phone first. Write the answers down and keep them with your school paperwork.

If your test truck has	You get	How to avoid it
An automatic transmission	E	Test in a truck with a manual transmission.
No air brakes	L	Test in a truck with air brakes, and pass the air brake knowledge test.
Air over hydraulic brakes	Z	Test in a truck with full air brakes.
A Class A combination with a pintle hook or other non-fifth wheel connection	O	Test in a tractor with a fifth wheel and a semi-trailer.

The Virginia manual adds one case. A Class A test in a combination that is not a tractor semi-trailer, but has a fifth wheel, also gets an O restriction.

What these cost you

An E, L, Z or O restriction limits which trucks you may drive. Under 49 CFR 383.95, the state must bar you from that kind of vehicle. This guide says nothing about how any employer treats them.

How to remove a restriction

Federal rule 49 CFR 383.135(b)(7) covers L, Z and E. You do not retake the whole skills test. Your state may give a modified test that shows you can run full air brakes, air over hydraulic brakes or a manual transmission. To remove L or Z you must also pass the air brake pre-trip inspection and the air brake knowledge test.

To remove O, you must retake all three skills tests in a representative tractor-trailer. That is 49 CFR 383.135(b)(8).

States list their own steps. South Carolina asks you to hold a CLP for 14 days, then pass the vehicle inspection and the on-road test for L and Z, but only the on-road test for E. Oregon lists the pre-trip, basic control and drive tests for L and E. Follow your state's list.

FMCSA says removing L, Z or E is not subject to entry-level driver training. Read our ELDT guide for who does need it. The rule's exception names the paragraph that covers L, Z and E, so ask your state about O. Some states ask you to hold a permit first, so see CDL permit cost by state for the fees.

Letters that mean two things

Some letters are also endorsement letters. On a CDL, N means a tank vehicle endorsement, and T means double or triple trailers. As a restriction, N means no Class A or B passenger vehicle. On a permit, P and X are restrictions. Check which box the letter is in.

States may add their own codes under 49 CFR 383.153. We did not list those. Texas, for example, lists the permit restriction as P33 and lists T as an automatic transmission restriction. New York uses A3, S1 and T1. If a letter is not in the table, read your state's list.

Prepare so you don't get L

You avoid L by passing the air brake knowledge test and testing in a truck with air brakes. See our air brakes practice test. Try 10 exam-style questions built from the official CDL manual.