The Ultimate CDL Guide: Everything Drivers Need to Know
A Commercial Driver’s License (CDL) is required by federal law and state governments to operate large or heavy vehicles in the United States. This license ensures that drivers can safely operate commercial trucks, buses, and other specialized vehicles.
Whether you want to start a trucking career or open your own company, a commercial driver’s license is essential. Below, we’ll explain what a CDL is, the different classes, endorsements, and the steps to obtain one.
What Is a Commercial Driver’s License?
A commercial driver’s license CDL gives you the legal right to drive commercial motor vehicles (CMVs). These include tractor-trailers, buses, and commercial vehicles that transport hazardous material.
The Commercial Motor Vehicle Safety Act of 1986 set national standards and required states to issue commercial driver’s licenses that meet federal testing rules. Since then, drivers must hold only one driver’s license at a time. For example, when you apply for a commercial learner’s permit (CLP), you’ll surrender your standard license, including an out-of-state CDL.
In short, a CDL is proof that you’re qualified to operate motor vehicles designed for business, including single vehicle operations, vehicles towing heavy loads, or those carrying passengers.
CDL Eligibility Requirements
To apply, CDL applicants must meet these testing requirements:
- Be at least 18 for commercial driving within one state, or 21 to drive in interstate commerce or haul hazardous materials.
- Hold a valid driver’s license with legal presence in the U.S.
- Pass a knowledge test and a written test on federal and state rules.
- Complete a driving test, including skills tests, a road test, and a CDL skills test.
- Obtain medical certification from certified medical examiners listed in the National Registry.
Meeting these requirements ensures that only trained commercial drivers are allowed commercial driving privileges.
How to Get a Commercial Driver’s License
The process varies by state, but here are the main steps:
Step 1: Get a Commercial Learner’s Permit (CLP)
Before taking the CDL skills tests, you’ll need a commercial learner’s permit CLP. This learner permit allows you to practice with a licensed CDL holder next to you.
To qualify, you’ll need:
- To pass the required knowledge tests.
- Provide proof of residency and medical examinations.
- Show that you meet federal motor carrier safety standards.
- Pay fees at your local DMV office.
Your permit will include an expiration date, so plan your training and driving test accordingly.
Step 2: Complete Entry-Level Driver Training (ELDT)
Federal rules require most new CDL Class A and Class B CDL applicants to complete entry-level driver training with a registered training provider. This training provider reports successful completion of your course to the FMCSA’s Training Provider Registry.
Without ELDT, you cannot take your CDL skills test or apply for certain endorsements.
Step 3: Take the CDL Skills Test
After at least 14 days with your CLP and completing training, you can schedule the CDL skills tests. These include:
- Vehicle Inspection Test – Show you can check a commercial motor vehicle CMV for safety.
- Basic Controls Test – Prove you can handle commercial vehicles using both manual transmission and automatic transmission systems.
- Road Test – Drive in traffic to show you can safely operate a commercial vehicle.
Passing the skills test earns you a valid CDL. Some states issue the CDL document the same day, while others mail it later. Always double-check it before leaving the DMV office.
Types of CDL Licenses
CDLs are divided into three main categories based on gross vehicle weight rating (GVWR) and gross combination weight rating (GCWR).
Class A CDL
A CDL Class A allows drivers to operate vehicles with a GVWR of 26,001 pounds or more, with trailers weighing over 10,000 pounds. Examples include:
- Tractor trailers
- Flatbeds
- Livestock carriers
- Large truck-trailer combinations
Class B CDL
A Class B CDL is for a single vehicle with a GVWR of 26,001 pounds or more, towing no more than 10,000 pounds. Examples include:
- Box trucks
- Dump trucks with small trailers
- Large passenger buses
- Straight trucks
Class C CDL
A CDL Class C is for passenger vehicles carrying 16+ people, including the driver, or vehicles transporting hazardous materials. Examples include:
- School bus operations
- Small hazmat vehicles
- Passenger vans
CDL Endorsements
Endorsements expand your commercial driving privileges. Common ones include:
- Hazardous Materials Endorsement (HME) – Also known as a hazmat endorsement, this requires a hazardous materials knowledge test, background check, and fingerprinting.
- Passenger Vehicle (P) – Needed to operate a bus or other passenger vehicle.
- School Bus (S) – Required to drive a school bus safely.
- Tank Vehicles (N) – For liquid or gas cargo.
- Double/Triple Trailers (T) – For pulling multiple trailers.
- Air Brakes – Needed to operate vehicles with air brake systems.
Some endorsements require both a written test and a skills test. The California DMV and other state offices manage endorsement rules and fees.
Medical Certification for CDL Holders
CDL holders must maintain current medical certification. This includes:
- Regular medical examinations by certified medical examiners.
- Submit medical variance information if applicable.
- Meeting federal regulations set by FMCSA.
If a driver completes rehab or treatment, they may qualify for reinstatement.
Drug and Alcohol Clearinghouse
The FMCSA’s Drug and Alcohol Clearinghouse is a secure system that tracks CDL holders with drug or alcohol violations. Also called the alcohol clearinghouse, it prevents unsafe commercial drivers from returning to work until they complete the required steps.
Employers and licensing offices must check the Clearinghouse before hiring or renewing a valid CDL.
Read More: The Guide to the FMCSA Clearinghouse
Maintaining a CDL
To keep your CDL license, you must:
- Stay compliant with federal regulations and state laws.
- Renew your CDL document before its expiration date.
- Keep up with the required medical certification.
- Follow rules for motor vehicles in interstate commerce.
Failing to comply can result in penalties, suspension, or loss of your license.
Services for Military Personnel and Veterans
Many states make it easier for veterans to obtain commercial driver’s licenses by recognizing military driving experience. Some waive the skills test if you’ve operated similar commercial motor vehicles while in service.
This support helps service members transition into civilian careers as commercial drivers.
For more information, visit the FMCSA Commercial Driver’s License (CDL) Program page.
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