What is the minimum age to get a CDL?

You must be at least 18 years old to obtain a CDL for intrastate (within-state) commercial driving. To drive in interstate commerce across state lines, you must be at least 21. Most trucking companies that hire drivers for interstate freight require drivers to be 21, even in states that allow 18-to-20-year-olds to hold CDLs for in-state use.

How long does it take to get a CDL?

Most CDL training programs range from 3 to 7 weeks. After completing training, you take the knowledge tests at your state DMV, receive a Commercial Learner's Permit (CLP), and must hold the CLP for at least 14 days before scheduling the skills test. Total time from starting training to receiving the CDL is typically 4 to 10 weeks depending on the program, test scheduling, and state processing times.

What is the difference between a CDL-A and CDL-B?

A Class A CDL authorizes operation of combination vehicles (tractor-trailers) with a gross combination weight rating of 26,001 pounds or more when the trailer exceeds 10,000 pounds GVWR. A Class B CDL covers single vehicles of 26,001 pounds GVWR or more without that trailer threshold — straight trucks, dump trucks, transit buses. Class A holders can drive Class B vehicles; Class B holders cannot drive combination vehicles that require Class A.

Do I need a CDL to drive for a carrier that already has authority?

Yes. A CDL is the individual driver license required to operate a commercial motor vehicle. It is separate from the carrier's operating authority (MC number and DOT number). Whether you are a company driver or an owner-operator, you need your own valid CDL to legally operate a CMV in interstate commerce.

Can a DUI or traffic conviction prevent me from getting a CDL?

Yes. Certain disqualifying offenses — DUI in a CMV (0.04% BAC limit), leaving the scene of an accident, using a CMV to commit a felony — can result in CDL disqualification. A first major offense typically results in at least a one-year disqualification. Serious traffic violations like excessive speeding or reckless driving can accumulate into disqualification. The state DMV and FMCSA both review driving history during the CDL application process.

Guide

CDL requirements explained

A commercial driver's license (CDL) is the federal license required to operate large trucks and other commercial motor vehicles in interstate commerce. Getting a CDL involves several steps — eligibility requirements, knowledge tests, a skills test, a DOT physical, and registration in the federal drug and alcohol clearinghouse. This guide explains what each step involves and what can disqualify a driver before or after getting a CDL.

CDL requirements are set federally by the FMCSA but administered by individual states, which may have additional requirements. Requirements also differ for intrastate vs. interstate operations and by vehicle type. Always verify current requirements with your state's motor vehicle or licensing agency and the FMCSA before applying.

CDL classes: A, B, and C

Not all CDLs are the same. The class you need depends on what you are driving:

Class A CDL: Required to operate any combination vehicle with a gross combination weight rating (GCWR) of 26,001 pounds or more — provided the towed vehicle has a gross vehicle weight rating (GVWR) exceeding 10,000 pounds. This is the class required for tractor-trailers, which is why it is the most common CDL in long-haul trucking.
Class B CDL: Required for single vehicles with a GVWR of 26,001 pounds or more, or to tow a vehicle weighing no more than 10,000 pounds. Class B covers large straight trucks, dump trucks, and most transit buses.
Class C CDL: Required for vehicles designed to transport 16 or more passengers (including the driver), or vehicles transporting hazardous materials that require placarding. Class C covers smaller passenger vehicles and certain specialty applications.

A Class A CDL holder can operate Class B and C vehicles. A Class B holder can operate Class C vehicles. Most people entering the trucking industry as long-haul or regional drivers pursue a Class A CDL.

Basic eligibility requirements

Before you can apply for a CDL, you need to meet these baseline requirements:

Age: You must be at least 18 years old for a CDL that authorizes intrastate (within your state) commercial driving. To drive in interstate commerce — across state lines — you must be at least 21. In practice, most trucking companies that hire drivers for interstate freight require drivers to be at least 21, even though some states permit 18-to-20-year-olds to hold CDLs for intrastate use.
Valid non-commercial driver's license: You need to hold a current regular driver's license in your state of domicile.
Residency: You must apply for your CDL in the state where you legally reside. You can only hold a CDL from one state at a time.
English language proficiency: FMCSA regulations require CDL holders to be able to read and speak English sufficiently to understand highway signs, respond to official inquiries, and make entries on reports and records.
Social Security number: Required for the CDL application in most states.

The knowledge tests

Before you take the skills test, you must pass written knowledge tests at your state's DMV or licensing agency. The specific tests you need depend on the class of CDL and any endorsements you are seeking.

General knowledge test

All CDL applicants must pass the general knowledge test. It covers: pre-trip vehicle inspection, basic vehicle controls, shifting and backing, coupling and uncoupling (for combination vehicles), pre-trip inspection procedures, cargo loading and securing, safe driving, hazardous conditions, and emergency procedures. The FMCSA's CDL manual — available in every state — is the primary study guide. States base their tests on the same federal content, though the specific questions differ.

Air brakes knowledge test

If the vehicle you will operate has air brakes — which includes most tractor-trailers — you must also pass the air brakes knowledge test. This covers how air brakes work, how to inspect them during the pre-trip, and how to handle air brake failures. If you do not take and pass the air brakes test, an air brakes restriction will be placed on your CDL, preventing you from operating vehicles with air brakes.

Combination vehicles knowledge test

Class A CDL applicants must pass the combination vehicles test, which covers the specific considerations for operating tractor-trailers and other combination units: coupling and uncoupling, rollover risks, rearward amplification in turns, and safe following distances for longer vehicles.

Endorsement knowledge tests

Endorsements require additional knowledge tests. Each endorsement has its own written test taken at the DMV before the CDL is issued with that endorsement. Common endorsements and their tests are described below.

The CDL skills test

Once you pass the required knowledge tests, you receive a commercial learner's permit (CLP). After holding the CLP for at least 14 days, you can schedule the skills test, which has three parts:

Pre-trip vehicle inspection

The examiner evaluates whether you can correctly inspect a commercial vehicle. You walk around the vehicle and verbally identify what you are checking and why — engine compartment, steering components, brakes, tires, wheels and rims, fuel system, lights, reflectors, coupling devices, cargo securement, and other safety components. This portion tests whether you know the vehicle well enough to identify safety defects before a trip.

Basic vehicle controls (skills pad test)

This test is conducted on a driving range or skills pad, not on public roads. It evaluates low-speed vehicle control — straight-line backing, offset backing, alley docking (backing into a simulated dock), parallel parking, and similar maneuvers. This portion tests whether you can control the vehicle at low speed in tight spaces, which is where most at-fault commercial vehicle incidents happen.

On-road driving test

The on-road portion evaluates driving on public roads. It covers: starting and stopping, left and right turns, merging, lane changes, highway driving, railroad crossings, curves, intersections, and traffic. The examiner watches for correct mirror use, following distance, lane positioning, and speed management. Any dangerous driving error can result in automatic failure.

You must bring a vehicle appropriate for the class of CDL you are testing for. If you are testing for a Class A CDL, you need a tractor-trailer combination, not a straight truck.

DOT physical and medical certificate

CDL holders who drive in interstate commerce must pass a physical examination performed by a FMCSA-certified medical examiner. The exam evaluates vision, hearing, blood pressure, urinalysis, and overall physical fitness to drive. Passing results in a medical examiner's certificate (medical card), which must be carried with your CDL when driving.

Medical certificates are valid for up to 24 months, but drivers with certain conditions (controlled blood pressure, diabetes managed with insulin under a waiver, sleep apnea) may receive shorter certification periods and need to recertify more frequently.

Common medical disqualifications include: certain heart conditions, seizure disorders without a period of seizure-free time, insulin-dependent diabetes (without a federal waiver), loss of limb (without a federal waiver), and vision that cannot meet federal standards even with correction. Many conditions that might disqualify a driver can be evaluated through a waiver or exemption process — consult with a medical examiner who works with commercial drivers if you have a condition that may be relevant.

FMCSA Drug and Alcohol Clearinghouse

As of January 2020, all CDL holders must be registered in the FMCSA Drug and Alcohol Clearinghouse. The Clearinghouse is a federal database that records drug and alcohol violations by commercial drivers. Employers are required to query the Clearinghouse before hiring a driver and then annually for current drivers.

A driver who tests positive for drugs or alcohol, refuses a test, or has a violation under the return-to-duty process is recorded in the Clearinghouse and cannot drive a CMV until they complete the return-to-duty process with a substance abuse professional. Violations stay in the Clearinghouse for five years from the date of the violation (or the date of successful completion of the return-to-duty process, whichever is later).

Every CDL applicant must also provide consent for employers to query the Clearinghouse. This has effectively made pre-employment drug history more transparent across the industry than it was before 2020.

CDL endorsements

Endorsements authorize a CDL holder to drive specific vehicle types or haul specific cargo. Each endorsement requires passing an additional knowledge test and, in some cases, an additional skills test or background check.

H — Hazardous materials: Required to transport placarded hazmat. Requires a Transportation Security Administration (TSA) threat assessment and background check, plus the hazmat knowledge test. The H endorsement is also subject to federal security requirements.
N — Tank vehicles: Required for vehicles with tank configurations. Includes the tank vehicle knowledge test covering liquid surge, emergency equipment, and inspection differences for tanks.
P — Passenger: Required for vehicles transporting 16 or more passengers. Requires a passenger knowledge test and a skills test in a passenger vehicle.
S — School bus: Required to drive a school bus. Requires a school bus knowledge test, skills test, and in most states, a background check.
T — Double/triple trailers: Required to pull double or triple trailer configurations. Requires a doubles and triples knowledge test. Not available in all states.
X — Tanker with hazmat: A combination of the H and N endorsements for drivers who haul hazmat in tank vehicles.

What can disqualify a CDL holder

Certain offenses result in CDL disqualification — loss of the CDL for a defined period or permanently. Major disqualifying offenses include:

Driving under the influence of alcohol (0.04% BAC limit for CMV drivers) or drugs
Leaving the scene of an accident
Using a CMV to commit a felony
Causing a fatality through negligent operation of a CMV
Refusing a drug or alcohol test

A first major offense typically results in at least a one-year disqualification. A second major offense results in lifetime disqualification. Some offenses — using a CMV to transport controlled substances, for example — result in lifetime disqualification on the first offense.

Serious traffic violations (excessive speeding, reckless driving, improper lane changes) can also lead to CDL disqualification when multiple violations occur within a defined period. CDL holders are held to a stricter traffic standard than regular drivers because of the size and weight of the vehicles they operate.

CDL training options

Since February 2022, FMCSA regulations require that first-time CDL applicants and applicants seeking certain upgrades or endorsements complete training from a provider listed on the FMCSA's Training Provider Registry (TPR). This means you cannot simply self-study and take the tests — you need to complete a program from a registered training school for Class A, Class B, and certain endorsements.

Training options include:

Private CDL schools: Typically 3 to 7 weeks, focused specifically on getting the CDL. Cost varies widely — $3,000 to $10,000 is common depending on location and program.
Carrier-sponsored training: Some large trucking companies offer tuition-free or tuition-reimbursed CDL training in exchange for a driving commitment (typically one year with that carrier after getting the CDL).
Community college programs: Some community colleges offer CDL programs, often at lower cost than private schools, and may offer financial aid or workforce development funding.

The FMCSA Training Provider Registry (TPR) at tpr.fmcsa.dot.gov lists all providers whose programs meet the federal minimum curriculum standards. Completing a program from a non-registered provider will not satisfy the federal entry-level driver training requirement.

After you get your CDL

A CDL is the license to operate the vehicle. Operating as a for-hire carrier also requires a DOT number, MC number (operating authority), appropriate insurance, and registration in the FMCSA systems. If you are driving for an established carrier as a company driver, the carrier handles those requirements. If you are starting as an independent owner-operator, the new carrier compliance checklist covers what you need beyond the CDL.

Common questions about getting a CDL

What is the minimum age to get a CDL?: You must be at least 18 years old for a CDL authorizing intrastate (within-state) driving. To drive in interstate commerce across state lines, the federal minimum is 21. Most long-haul carriers require drivers to be 21 regardless of state rules, partly because insurance underwriters set their own age minimums for interstate truck drivers.
How long does it take to get a CDL from start to finish?: Most CDL training programs run 3 to 7 weeks. After training, you take knowledge tests at your state DMV, receive a Commercial Learner's Permit (CLP), and must hold it for at least 14 days before scheduling the skills test. Total time from starting school to holding a CDL is typically 4 to 10 weeks depending on the program length, test scheduling, and state processing times.
What is the difference between a CDL-A and a CDL-B?: A Class A CDL authorizes combination vehicles — tractor-trailers — where the GCWR is 26,001 pounds or more and the trailer exceeds 10,000 pounds GVWR. A Class B covers single heavy vehicles above 26,001 pounds GVWR — straight trucks, dump trucks, transit buses. Class A holders can legally drive Class B vehicles. Class B holders cannot drive combination vehicles requiring Class A.
Can I fail the CDL skills test for mistakes during the pre-trip inspection?: Yes. The pre-trip inspection is a graded portion of the skills test. Failing to identify safety-critical components, missing required items, or not knowing what to look for can result in a failing score on that section. Some states allow you to fail one section and retake only that part; others require retesting all three sections. Know your state's retesting rules before you test.
Do I need a CDL to drive a box truck or moving truck?: It depends on the vehicle's GVWR. Box trucks with a GVWR of 26,000 pounds or less do not require a CDL. Vehicles with a GVWR of 26,001 pounds or more require at least a Class B CDL. Most large rental moving trucks (26-foot and larger) exceed 26,000 pounds GVWR, but rental companies sometimes allow non-CDL drivers to operate them under private carrier exemptions. Commercial for-hire operation of those vehicles requires the appropriate CDL class.