2025 Edition

The Commercial Driver's License (CDL) Test Guide

The CDL Test Summary
What: The commercial driver
Who: Anyone wishing to work as a commercial truck or bus driver needs to have a CDL.
Where: CDL exams are administered by each state
When: The federally mandated minimum age to obtain a CDL is 21 years of age. Some states allow drivers between the ages of 18 and 20 to obtain CDLs for intrastate driving only. State requirements vary as to whether exams must be scheduled in advance.
How: All classes of CDL tests require a written knowledge test and a driving skills test that must be taken in a vehicle representing the type that will be operated by the individual.
Type: General knowledge tests are written exams issued by the state. Driving skills tests must be taken in a vehicle representing the one that will be operated. Endorsement exams may require a combination of written and driving skills tests.
Why: CDLs are issued to operators of commercial motor vehicles to insure that they are knowledgeable and well skilled in safely and effectively operating the vehicles. Federal mandates require states to adhere to a minimum set of standards to insure safety.
Time: Test times will vary by state and by type of test taken. There are written and driving skills tests for the general knowledge portion of the CDL and for all endorsements and these vary in length, depending on the vehicle.
Language: English, Spanish and Haitian Creole (FL)
Preparation: There are many driving schools and employers that offer training in the operation of CMVs and help prepare individuals to take the tests. There are also informational manuals available.
Cost: The cost also varies state to state. Applicants can expect to pay an application fee, an exam fee, a license fee, as well as fees for any endorsements.

By Andrea Cohen, Tests.com Contributing Writer

All drivers of commercial motor vehicles are required to have a commercial drivers’ license (CDL). Since 1986, it has been mandatory for all states to adhere to federal standards when issuing licenses for drivers of commercial motor vehicles (trucks and buses), in response to the Commercial Motor Vehicle Safety Act of 1986. Licenses are issued by the state in which an individual resides, but the Federal Highway Administration has developed the standards by which states must abide when testing and issuing licenses for commercial drivers. Before earning a CDL, drivers need to pass written knowledge and driving skills tests related to the type of vehicle they are being licensed to drive.

Any individual wishing to drive a CMV, whether intrastate or interstate should take the CDL test, and any appropriate endorsement tests, in order to be qualified to operate a commercial vehicle. There are some instances where a portion of the test can be waived, including active duty military drivers, firefighters, emergency response vehicle drivers, farmers and snow removal operators in small communities, but this is dependent on the state, and certain conditions may apply. Different states have varying requirements as to who is required to have a CDL, depending on the vehicle being driven.

CDL Classes and Endorsements

There are three classes of CDLs:

Class A - Any combination of vehicles with a gross vehicle weight (GVWR) of 26,001 lbs or more provided the GVWR of the vehicle(s) being towed is in excess of 10,000 lbs.
Class B - Any single vehicle with a GVWR of 26,001 lbs or more, or any such vehicle towing a vehicle not in excess of 10,000 lbs GVWR.
Class C - Any single vehicle, or combination of vehicles, that does not meet the definition of Class A or Class B, but is either designed to transport 16 or more passengers, including the driver, or is placarded for hazardous materials.

In addition to the three classes of CDLs that can be issued, if a driver operates a specific type of commercial motor vehicle they may be required to pass additional tests and must obtain the following endorsements on their CDL:

H - Hazardous Materials (written test and background check)
N - Tank Vehicle (written test)
P - Passenger Vehicles (written and skills tests)
S – School Bus (written and skills tests, background check, sex offender registry check and “P” endorsement)
T - Double/Triple Trailers (written test) – must already have a Class A CDL
X - Combination of Tank Vehicle and Hazardous Materials (written test)

Endorsements can only be obtained after a CDL has been issued.

CDLs can also be issued with or without air brake restrictions, depending on the vehicle used to take the exam.

The CDL Test

Each individual state develops and administers their own CDL tests and license issuing requirements, but all tests and licensing requirements must, at minimum, meet the federally-mandated standards. There can be third party testers for the skills portion of the exams, and these can be offered by governmental departments and agencies, private companies, truck driver training facilities or employers, depending on state requirements. The requirements for third party testing includes making sure the tests are the same as those given by the state and that examiners meet the same qualifications as state examiners. States must conduct random inspections, audits and examinations at least once a year to evaluate third-party testing programs.

Each state must meet at least these federal standards:

A minimum of 30 questions must be on the general knowledge test.
At least 80% of questions on the general and endorsement knowledge tests must be answered correctly in order to pass.
The driving skills portion of the test must be taken in the type of vehicle that the individual is requesting a license to operate and all required skills must be successfully performed.

The written knowledge portion of the exam tests general driving knowledge and safety issues related to operation of the vehicle. The driving skills portion of the exam includes a pre-trip vehicle inspection, demonstration of basic vehicle control and a road test in a variety of traffic situations. The driving skills test must be taken in a vehicle that is representative of the one the applicant is expected to operate.

CDL Test Requirements

Minimum age requirements, medical and driver qualifications are all determined by the state issuing the CDL if the driver is only operating on an intrastate basis. For any drivers operating CMVs interstate, federal driver qualifications must be adhered to. All applicants must also have a valid social security number.

Minimum age is the main prerequisite, and the Department of Transportation requires the minimum age as 21 to apply for a CDL for interstate drivers or in order to transport hazardous materials. Some states may allow drivers who are 18 – 20 years old to apply for a CDL that is valid only within the state of residence.

It is not required that any training or education be completed prior to taking the CDL test. In order to pass the CDL test and obtain a license, a written test of knowledge must be passed (at least 80% of the questions correct). A driving skills test must also be passed in a vehicle similar to the one the driver is expected to operate, and all required driving skills and maneuvers must be performed correctly.

Medical certification may be required, depending on the class and type of vehicle being driven. For example, drivers transporting over 15 passengers, operating vehicles over 10,000 lbs. or transporting hazardous materials must carry a medical certificate that has been approved by the Department of Transportation (DOT). Candidates must also pass an eye examination.

Exam Costs

Every state independently determines fees associated with each portion of the CDL tests, as well as for the endorsement exams. Some states charge separately for each individual portion of the test and some charge together. Fees can be charged for tests, licenses, endorsements or removing restrictions and vary among states.

Interested in obtaining a Commercial Drivers License (CDL)? Check out our Commercial Drivers License Test Directory.

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