Class A and Class B Licenses: What They Cover and How They Differ

Commercial driving isn't one-size-fits-all. The federal government divides commercial driver's licenses into classes based on the weight and type of vehicle being operated — and Class A and Class B licenses represent two distinct tiers of that system. Understanding what separates them matters whether you're entering the trucking industry, driving a passenger bus, or exploring a career that puts you behind the wheel of something heavier than a standard car.

What Is a Class A CDL?

A Class A Commercial Driver's License (CDL) authorizes the holder to operate combination vehicles — typically a tractor pulling a trailer or multiple trailers — with a Gross Combination Weight Rating (GCWR) of 26,001 pounds or more, provided the vehicle being towed exceeds 10,000 pounds.

In practical terms, Class A covers:

• 18-wheelers and semi-trucks
• Tractor-trailers and flatbeds
• Livestock carriers
• Tanker combinations
• Double and triple trailers (with appropriate endorsements)

Class A is the broadest CDL class. With the right endorsements, a Class A holder can also operate most Class B and Class C vehicles. This makes it the most versatile commercial license available.

What Is a Class B CDL?

A Class B CDL covers single vehicles with a Gross Vehicle Weight Rating (GVWR) of 26,001 pounds or more, or a vehicle towing something that does not exceed 10,000 pounds.

Class B vehicles commonly include:

• Straight trucks and large delivery vehicles
• City transit and intercity buses
• School buses
• Dump trucks with small trailers
• Segmented buses

Class B does not authorize the holder to operate combination vehicles where the trailer exceeds the 10,000-pound threshold. That distinction is the core dividing line between the two classes.

Class A vs. Class B: A Side-by-Side Look

Federal Framework, State Administration

CDL classifications are established under federal regulations — specifically the Federal Motor Carrier Safety Administration (FMCSA) rules — which means the Class A and Class B definitions are consistent nationwide. However, the process of obtaining either license is administered at the state level.

That means:

• Testing requirements (written knowledge tests, pre-trip inspection, skills tests) follow federal guidelines but are conducted by your state's DMV or licensing agency
• Fees vary by state and sometimes by license class
• Scheduling, wait times, and third-party testing options differ from state to state
• Medical certification requirements (a valid DOT physical) are federally mandated but processed through your state's records system

What's Required to Get a Class A or Class B CDL 🚛

Regardless of which class you're pursuing, the path generally involves:

1. Obtaining a Commercial Learner's Permit (CLP) — a prerequisite before taking the CDL skills test. Requires passing one or more written knowledge tests.
2. Holding the CLP for a minimum period — federally set at 14 days before skills testing
3. Passing a CDL skills test — which includes a vehicle inspection, basic vehicle control, and an on-road driving test
4. Submitting a DOT medical examination certificate — drivers must meet federal physical standards
5. Meeting age requirements — generally 18 for intrastate (within-state) driving, 21 for interstate (across state lines) commercial operation, though rules around younger CDL holders are evolving under recent federal pilot programs

Class A testing is more involved than Class B because it includes combination vehicle operation. If you're training for Class A, expect the skills test to cover coupling and uncoupling procedures, backing a trailer, and handling longer vehicle combinations.

Endorsements That Expand What You Can Do

Both Class A and Class B licenses can be expanded with endorsements — additional authorizations for specific vehicle types or cargo. Common endorsements include:

• H — Hazardous materials (requires TSA background check)
• N — Tank vehicles
• P — Passenger transport
• S — School bus
• T — Double/triple trailers (Class A only)
• X — Combination of tank and hazmat

Each endorsement involves an additional knowledge test. Some, like hazmat, have federal background check requirements layered on top of state testing.

Restrictions Can Also Apply

Just as endorsements expand what a license covers, restrictions can limit it. A driver who tests in a vehicle with an automatic transmission, for example, may receive a restriction prohibiting operation of manual transmission vehicles. Restrictions show up directly on the license and affect what work a driver is legally authorized to perform.

What Shapes Your Specific Path 📋

Even within a well-defined federal framework, individual outcomes vary based on:

• Your state's fee schedule for CLPs, CDL issuance, and endorsements
• Whether your state uses third-party CDL testing or requires testing at a state facility
• Your driving record — disqualifying offenses, prior suspensions, or out-of-state violations can affect eligibility
• Your employment situation — some employers sponsor CDL training and testing; others require you to arrive licensed
• Which endorsements your intended work requires — and which knowledge tests you'll need to pass before your skills test date

The federal rules set the floor. Your state's DMV sets the process, the fees, and the scheduling — and those details can differ significantly from one state to the next.