Set by the FMCSA and the same in every state, on top of your state's CDL manual: classes, endorsements, the medical card, alcohol, hours and what costs a CDL.
At least 80% on each knowledge test, in every state. The federal testing standard sets it, and every test is scored by itself, so passing one never makes up for another. 49 CFR 383.135, opens in a new tab
Practice the CDL knowledge testsThe class depends on how heavy the vehicle is, what it pulls and what it carries.
26,001 lb or more in all, towing over 10,000 lb
Tractor-trailers, truck and trailer combinations, livestock haulers
Covers Class B and C too, given the matching endorsements.
26,001 lb or more, towing 10,000 lb or less
Straight trucks, dump trucks, city and tour buses
Covers Class C as well, given the matching endorsements.
Under the A and B weights
Vans and buses for 16 or more people, or vehicles hauling placarded hazmat
Needs the Passenger or Hazmat endorsement that fits the vehicle.
Federal vehicle groups, 49 CFR 383.91.
Endorsements are letters that add a vehicle or load you may drive. Restrictions are letters that take one away, usually because of the vehicle you tested in.
| Letter | Lets you drive | You pass | On a learner's permit? |
|---|---|---|---|
| T | Double or triple trailers | Knowledge test | No |
| P | Passenger vehicles | Knowledge and skills tests | Yes |
| N | Tank vehicles | Knowledge test | Yes |
| H | Placarded hazardous materials | Knowledge test and a TSA security check | No |
| X | Tank and hazmat together | The N and H tests | No |
| S | School buses | Knowledge and skills tests | Yes |
| Letter | Means | Usually because you |
|---|---|---|
| L | No vehicles with air brakes | Failed or skipped the air brake test, or tested without air brakes |
| Z | No full air brakes | Tested in a vehicle with air-over-hydraulic brakes |
| E | No manual transmission | Tested in an automatic |
| O | No tractor-trailer with a fifth wheel | Tested a Class A on a pintle hook or similar hitch |
| M | Passenger vehicles up to Class B only | Passenger skills test taken in a Class B bus |
| N | Class C passenger vehicles only | Passenger skills test taken in a Class C vehicle |
| K | Within your state only | Under 21, or not qualified for interstate driving |
| V | Medical variance on record | Driving under an FMCSA medical exemption or skill evaluation |
A restriction comes off when you pass the test in a vehicle that has the missing feature. Codes: 49 CFR 383.153.
A certified medical examiner checks these before you can drive a commercial vehicle.
The examiner also looks at heart and breathing conditions, blood pressure, seizures and other conditions that could cause sudden loss of control. Insulin-treated diabetes no longer rules a driver out: a treating doctor fills in an assessment form first. A lost limb can be cleared through a skills evaluation.
Physical qualifications, 49 CFR 391.41 to 391.46.
Commercial drivers have a much lower alcohol limit than car drivers.
Carrying alcohol in the cab on duty is not allowed either, unless it's part of the load you were hired to haul. Drivers are tested before hiring, at random, after some crashes and on reasonable suspicion.
Alcohol and drug rules, 49 CFR parts 382 and 392.
How long you may drive and work before resting, when you haul freight.
Property-carrying drivers, 49 CFR 395.3. Bus and other passenger drivers follow their own, slightly different limits.
Federal rules set the shortest time off the road; a state may add more. Some of these count even when they happen in your own car.
Driving under the influence in any vehicle, 0.04 or above while driving a CMV, refusing an alcohol test, leaving a crash scene, a felony using a vehicle, causing a death by negligent CMV driving.
Speeding 15 mph or more over the limit, reckless driving, erratic lane changes, tailgating, texting or a hand-held phone in a CMV, driving a CMV without the right license.
Not slowing to check the tracks, not stopping when you must, starting across without room to clear them, or getting stuck on the rails.
Driving while you or your vehicle has been ordered off the road.
Disqualification tables, 49 CFR 383.51.
If your military job in the past year was driving a heavy vehicle (for example Army Motor Transport Operator 88M, Air Force Vehicle Operator 2T1, Marine Corps Motor Vehicle Operator 3531 or Navy Equipment Operator), a state may skip your knowledge test, your skills test or both. You need a clean record: one license at a time, no suspensions, no disqualifying offenses and no at-fault crash.
Military waivers, 49 CFR 383.77; your state's CDL office has the form.
Each state issues its own CDLs, but it must follow the federal standards for testing, licensing and disqualification, and drivers must meet the federal driver qualifications. That's why these rules are the same in every state, while fees, offices and some details differ. 49 CFR Part 383
Since February 7, 2022, new drivers train first, at a school or carrier listed on FMCSA's Training Provider Registry. It applies to a first Class A or B license, a move up from B to A, and a first endorsement for passengers, school buses or hazmat, and the state confirms the training online before the matching test. 49 CFR 380.603
At least 14 days after it is first issued before you can take the skills test. A CLP can be valid for no more than one year from its first issue without retaking the knowledge tests. 49 CFR 383.25
At least 21 to drive a commercial vehicle across state lines under the federal driver rules. Most states issue CDLs from age 18 for driving only within that state. 49 CFR 391.11
Yes. A qualified driver must read and speak English well enough to talk with the public, understand traffic signs and signals, answer officials and fill in reports and records. 49 CFR 391.11
No. A person who drives a commercial vehicle may never have more than one driver’s license at a time. 49 CFR 383.21
Only a non-domiciled CLP or CDL, and only with H-2A, H-2B or E-2 status (FMCSA’s final rule, in force since March 16, 2026); a work permit (EAD) no longer qualifies. Every transaction is in person, the state checks your status through SAVE each time, and the license lasts until your I-94 date or one year, whichever is sooner. States that could not meet the rule had to pause issuing them, so check your state’s CDL page. FMCSA non-domiciled CDL FAQs
Your exam must be done by a medical examiner on FMCSA's National Registry, and the result goes to your state electronically. Once it arrives, your record shows you as medically certified; in most states a paper card is no longer needed at the counter. FMCSA National Registry
FMCSA's online record of commercial drivers' drug and alcohol testing violations, such as a failed or refused test. Employers must check it before you start driving for them and at least once a year after that. 49 CFR 382.701
Yes. Since November 18, 2024, every licensing office looks a driver up there before a new, renewed or upgraded CLP or CDL, and turns away anyone listed as prohibited. A current holder who becomes prohibited loses the commercial privilege until the return-to-duty process is done. 49 CFR 383.73
Yes. Tell your employer in writing within 30 days of being convicted of any traffic violation except parking, in any vehicle, even your own car. 49 CFR 383.31
Tell your employer before the end of the business day after the day you get the notice. 49 CFR 383.33
Your state's knowledge tests are written from its own CDL manual, so our practice questions come from that manual too. Check your state's licensing office for its fees, forms and offices.
Each state's knowledge tests come from its own CDL manual. Pick yours:
