Complete Guide to Commercial Driver's Licenses
A Commercial Driver's License (CDL) is required to operate large or heavy vehicles in the United States. This guide covers everything you need to know about CDL classes, endorsements, and requirements.
CDL Classes
There are three classes of CDLs, each allowing you to operate different types of vehicles:
Class A CDL
The most versatile license, required for:
- Tractor-trailers (semi-trucks, 18-wheelers)
- Truck and trailer combinations over 26,001 lbs GVWR (where trailer exceeds 10,000 lbs)
- Tanker trucks
- Flatbeds
- Livestock carriers
Typical jobs: OTR driver, regional driver, tanker driver, flatbed driver
Class B CDL
Required for single vehicles over 26,001 lbs GVWR, or towing a trailer under 10,000 lbs:
- Straight trucks (box trucks, delivery trucks)
- Large buses (city buses, tourist buses, school buses)
- Dump trucks with small trailers
- Segmented buses
Typical jobs: Delivery driver, bus driver, dump truck operator
Class C CDL
Required for vehicles designed to transport 16+ passengers (including driver) or hazardous materials:
- Small HazMat vehicles
- Passenger vans (16+ passengers)
- Small buses
CDL Endorsements
Endorsements expand what you can legally haul. Each requires passing an additional knowledge or skills test:
| Code | Endorsement | Allows You To |
|---|---|---|
| H | Hazardous Materials | Transport hazardous materials (requires TSA background check) |
| N | Tank Vehicle | Drive tank vehicles (liquid or gas cargo) |
| P | Passenger | Transport passengers (buses) |
| S | School Bus | Operate school buses |
| T | Double/Triple Trailers | Pull double or triple trailers |
| X | HazMat + Tank | Combination of H and N endorsements |
How to Get Your CDL
- Meet basic requirements: Be at least 18 (21 for interstate), have a valid driver's license, pass a DOT physical
- Get your Commercial Learner's Permit (CLP): Pass the written knowledge tests at your DMV
- Complete training: Attend a CDL school or company-sponsored training program
- Pass the skills test: Pre-trip inspection, basic controls, and road test
- Apply for your CDL: Submit paperwork and fees to your state DMV
Entry-Level Driver Training (ELDT)
As of February 2022, new CDL applicants must complete ELDT from a registered training provider. This includes:
- Theory (classroom) instruction
- Behind-the-wheel training with a qualified instructor
- Range training for vehicle control maneuvers
Medical Requirements
All CDL holders must pass a DOT physical examination and maintain a valid Medical Examiner's Certificate. The exam covers:
- Vision (at least 20/40 in each eye)
- Hearing ability
- Blood pressure and cardiovascular health
- Drug and alcohol screening