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Who needs a CDL, and the three license classes

General Knowledge4 minManual section 1 (Intro)

Federal law makes every state test commercial drivers to the same minimum standard. The first thing to learn is when a vehicle needs a CDL and which class (A, B or C) fits it. Weight ratings, actual weights and what you carry decide this — not the size of the cab or how the truck looks.

When you must have a CDL

You need a CDL to drive a commercial motor vehicle (CMV) that meets any one of these:

  • A single vehicle whose GVWR or actual weight, whichever is greater, is 26,001 lb or more.
  • A combination with a GCWR of 26,001 lb or more, when the towed unit(s) have a GVWR of more than 10,000 lb.
  • A vehicle designed to carry 16 or more passengers, counting the driver.
  • A vehicle of any size that must show hazardous materials placards, or that carries a select agent or toxin listed in federal rule 42 CFR Part 73.

GVWR is the manufacturer’s loaded-weight rating. CDL weight thresholds compare the rating and actual weight and use the greater value (49 CFR 383.5). An empty truck rated at 33,000 lb still meets the weight threshold. GCWR has its own federal definition; check both vehicle and combination limits. In the class examples below, stated weights assume the applicable greater-of-rating-or-actual comparison. The CDL definition here is specific to Part 383; it is not a universal definition of all federally regulated commercial vehicles.

Hauling hazmat also needs a federal background check and fingerprinting through the Department of Homeland Security (the TSA). Your state may also count more vehicles as CMVs than the federal rule does.

Class A — combination vehicles

Class A: any combination with a GCWR of 26,001 lb or more, as long as the towed vehicle(s) have a GVWR of more than 10,000 lb.

Most Class A vehicles are trucks: a tractor-semitrailer or a truck pulling a trailer. A few cities also use tractor-trailer buses.

Class A takes the most skill. Because a Class A driver has the skills for the smaller classes, a Class A license also lets you drive Class B and Class C vehicles (you still need any endorsements those vehicles require).

Class B — heavy straight vehicles

Class B: any single vehicle with a GVWR of 26,001 lb or more, or such a vehicle towing a vehicle of 10,000 lb GVWR or less.

Examples: straight trucks, dump trucks, large buses (including articulated buses, the "bendy" city buses).

A Class B license also covers Class C vehicles, but not Class A.

Watch the trailer number: a 30,000-lb truck towing an 8,000-lb trailer is Class B (trailer is 10,000 lb or less). The same truck towing a 12,000-lb trailer is Class A (trailer is over 10,000 lb).

Class C — small vehicles that carry people or hazmat

Class C: a single vehicle with a GVWR under 26,001 lb (or one towing 10,000 lb or less). It needs a CDL only if it:

  • is designed to carry 16 or more passengers, including the driver, or
  • carries hazardous materials in amounts that require placards (49 CFR Part 172, Subpart F), or any select agent or toxin (42 CFR Part 73).

Why small vehicles need a CDL: for Class C the license is based mainly on the cargo, not the size. A crash with a van full of people or a load of hazmat can be a disaster, so even these smaller vehicles need a driver with special knowledge.

A bus can be Class A, B or C. Capacity for 15 people including the driver does not by itself reach the federal CDL passenger threshold. Weight, hazardous materials and state rules still need checking.

State options

The federal rule is a minimum. A state may require a CDL for more drivers and vehicles — for example, for buses built for fewer than 16 passengers. Going beyond the federal standard is allowed; the state then decides which tests those drivers take.

References and scope

The topic reference is listed below. Sources support verification; the lesson itself is here. The current content needs technical and language review before public launch.

Manual reference: 1 (Intro)

49 CFR 383.5 ↗Official CDL handbook · Utah ↗StatesOur editorial approach

Put it into practice

Educational questions with explanations. The answer review also works without the interactive quiz.

Preparing your questions…

Review questions with answers

  1. A single vehicle needs a CDL when its GVWR is at least:
    1. 10,001 lb
    2. 16,000 lb
    3. 26,001 lb
    4. 33,000 lb
    Show answer
    26,001 lb

    Any single vehicle with a GVWR of 26,001 lb or more needs a CDL.

  2. A combination with a GCWR of 26,001 lb or more is Class A when the towed unit's GVWR is:
    1. 10,000 lb or less
    2. More than 10,000 lb
    3. More than 26,000 lb
    4. At least 5,000 lb
    Show answer
    More than 10,000 lb

    Class A requires the towed vehicle(s) to have a GVWR of more than 10,000 lb.

  3. A vehicle under 26,001 lb needs a CDL if it is designed to carry how many people?
    1. 8 or more, including the driver
    2. 10 or more, not counting the driver
    3. 15 or more, not counting the driver
    4. 16 or more, including the driver
    Show answer
    16 or more, including the driver

    Vehicles designed for 16 or more people, counting the driver, need a CDL.

  4. A small pickup truck hauling hazardous materials that require placards:
    1. Needs a CDL with the right endorsement
    2. Never needs a CDL because it is under 26,001 lb
    3. Needs a CDL only if it crosses state lines
    4. Needs only a regular license and a permit
    Show answer
    Needs a CDL with the right endorsement

    Any size vehicle that must be placarded for hazmat needs a CDL (with the H endorsement).

  5. A straight truck with a GVWR of 30,000 lb towing a trailer with a GVWR of 8,000 lb requires which class?
    1. Class A
    2. Class C
    3. Class B
    4. No CDL
    Show answer
    Class B

    A single vehicle of 26,001+ lb towing 10,000 lb or less is Class B.

  6. The same 30,000-lb truck now tows a trailer with a GVWR of 12,000 lb. Which class is needed?
    1. Class A
    2. Class B
    3. Class C
    4. Class B with a T endorsement
    Show answer
    Class A

    The GCWR is over 26,001 lb and the towed unit is over 10,000 lb, so it is Class A.

  7. A driver with a Class A CDL (and needed endorsements) may also drive:
    1. Only Class A vehicles
    2. Class B and Class C vehicles
    3. Class B vehicles but not Class C
    4. Any vehicle without endorsements
    Show answer
    Class B and Class C vehicles

    Class A includes the skills for B and C, so a Class A holder may drive B and C vehicles with the needed endorsements.

  8. For Class C vehicles, the license requirement is based mainly on:
    1. The length of the vehicle
    2. The number of axles
    3. The engine size
    4. The type of cargo or passengers carried
    Show answer
    The type of cargo or passengers carried

    Class C is in the CDL program because of what it carries: 16+ people or placarded hazmat.

  9. Which statement about buses is correct?
    1. All buses are Class C
    2. A bus may be Class A, B or C depending on its GVWR and whether it is a combination
    3. All buses are Class B
    4. Buses never need a CDL if they carry fewer than 30 people
    Show answer
    A bus may be Class A, B or C depending on its GVWR and whether it is a combination

    Bus class depends on GVWR and whether it is a combination vehicle.

  10. A state may require a CDL for vehicles that the federal rule does not cover, such as buses for fewer than 16 passengers.
    1. True
    2. False
    Show answer
    True

    The federal rule is a minimum; states may include more drivers and vehicles.

  11. Which agency requires a background check and fingerprints for the hazardous materials endorsement?
    1. The Department of Agriculture
    2. The Environmental Protection Agency
    3. The Department of Homeland Security (TSA)
    4. The Department of Energy
    Show answer
    The Department of Homeland Security (TSA)

    Federal rules through Homeland Security (the TSA) require a background check and fingerprints for H.

  12. GVWR means:
    1. What the vehicle weighs today on a scale
    2. The maximum loaded weight the maker rates for a single vehicle
    3. The weight of the cargo only
    4. The weight of the empty vehicle
    Show answer
    The maximum loaded weight the maker rates for a single vehicle

    GVWR is the manufacturer's rated maximum loaded weight for one vehicle.

  13. Which of these is a typical Class B vehicle?
    1. A tractor pulling a semitrailer
    2. A pickup towing a 5,000-lb boat
    3. A 12-passenger van
    4. A large city bus with a GVWR of 36,000 lb
    Show answer
    A large city bus with a GVWR of 36,000 lb

    A single vehicle of 26,001 lb or more, such as a large bus, is Class B.

  14. A truck rated at 33,000 lb GVWR is driven empty and weighs 15,000 lb today. Does the driver need a CDL?
    1. No, because it weighs less than 26,001 lb today
    2. Yes, because the GVWR is 26,001 lb or more
    3. Only when it is loaded
    4. Only on interstate highways
    Show answer
    Yes, because the GVWR is 26,001 lb or more

    The greater of the rating and actual weight applies. Here the 33,000 lb rating exceeds the threshold.