What Is a CDL License?
TL;DR
A CDL (Commercial Driver's License) is the license you need to legally drive big commercial vehicles in the US. It comes in 3 classes. Class A covers semi-trucks and tractor-trailers, Class B covers straight trucks and buses, and Class C covers vehicles carrying 16 or more passengers or hazardous materials. The short version: if your vehicle is over 26,001 lbs GVWR, or it hauls passengers or hazmat, you need a CDL.
CDL Explained: What It Is and Who Needs One
A Commercial Driver's License (CDL) is a federal and state-issued license that lets you legally operate large commercial motor vehicles (CMVs) here in the US. The rules come from the Federal Motor Carrier Safety Administration (FMCSA), but your state is the one that actually issues the license. You'll need a CDL if you drive any of these:
- Vehicles with a Gross Vehicle Weight Rating (GVWR) over 26,001 lbs
- Vehicles towing a trailer rated over 10,001 lbs GVWR, when the combined weight tops 26,001 lbs
- Vehicles built to carry 16 or more passengers, and that count includes you, the driver
- Vehicles hauling hazardous materials that require placards
The 3 CDL Classes: A, B, and C
Which CDL you get comes down to what you plan to drive. There are three classes, and here's how I explain them to students:
- Class A CDL: This is the big one. Semi-trucks, tractor-trailers, livestock haulers, flatbeds, basically any combination vehicle over 26,001 lbs with a towed unit over 10,001 lbs. It also pays the most.
- Class B CDL: Straight trucks, large buses, dump trucks, delivery trucks. Think single vehicle over 26,001 lbs. If you hold a Class B, you can drive Class C vehicles too.
- Class C CDL: This covers vehicles that carry 16 or more passengers or haul hazardous materials but don't fall under Class A or B. Small hazmat vehicles and airport shuttles are good examples.
CDL Endorsements: What They Let You Do
Endorsements are add-ons you put on your CDL so you can drive specialized vehicles or haul certain cargo. Here are the ones that come up most:
- H (Hazardous Materials): you need this to haul hazmat cargo
- N (Tank Vehicles): you need this to drive tanker trucks
- P (Passenger): you need this to carry 16 or more passengers, like buses and shuttles
- S (School Bus): you need this to drive school buses
- T (Doubles/Triples): you need this to pull double or triple trailers
- X: this one rolls N and H together (tank plus hazmat)
Start Preparing for Your CDL Today
Before you ever touch a truck, you've got to pass the CDL knowledge test, and it trips up more people than you'd think. Our free 2026 practice tests cover everything from General Knowledge to the specialized endorsements.
Take Free CDL Practice Test →