CDL General Knowledge Test: Topics, Scores, and Endorsements

What the general test is for

The general knowledge test checks whether an applicant has the knowledge needed to operate a commercial motor vehicle safely. The federal rule also requires the test to check knowledge for the vehicle group or endorsement the applicant wants. A class label alone does not describe every test that may apply. Review the requirements for the vehicle and work you plan to do.

Source: FMCSA

The federal standard points to areas of knowledge in the commercial driver rules. General knowledge includes safe operation, inspection, and related driving duties. Each endorsement adds specialized subject matter. Use the applicable state commercial driver handbook to identify the topics for your selected vehicle group and tests.

Source: FMCSA

Question counts depend on the state test

Federal rules require each state test method to set a question count and include a prescribed number from each knowledge area. The federal rule does not provide one question count for all versions. Check your state licensing agency for the current test length and the count for each test you need.

Source: FMCSA

Do not treat a practice exam length as proof of your state's official test length. A practice set is a way to review material. The state agency controls its testing process within federal requirements. Confirm the current information before you schedule or travel to a test location.

Source: FMCSA

Apply the passing score to each test

A driver applicant must answer at least 80 percent correctly on each knowledge test to pass that test. This is a federal minimum passing score. If a person takes more than one knowledge test, the score applies to each test rather than to one combined total across all tests.

Source: FMCSA

Use 80 percent as a study checkpoint for each separate subject. If a mock test combines questions from several subjects, review the topic-level results instead of relying only on the combined score. This approach can show that one endorsement or knowledge area needs more work.

Source: FMCSA

Check which endorsements require a test

Federal rules require specialized tests for each endorsement, in addition to the knowledge and skills tests for the commercial license. The listed endorsement areas include passenger, school bus, tank vehicle, hazardous materials, and doubles or triples. An endorsement test checks knowledge tied to the added vehicle or duty.

Source: FMCSA

Start with the state agency's endorsement list. Select each endorsement that matches the work you plan to do. Then study its subject areas separately from general knowledge. Some applicants need more than one endorsement test, and each test has its own required passing score.

Source: FMCSA

Separate knowledge tests from the skills test

Knowledge tests and the driving skills test are different parts of CDL qualification. Federal rules describe a skills test with a pre-trip vehicle inspection, basic vehicle control, and on-road skills. The knowledge score does not replace a required skills test. Confirm which steps apply to your permit, vehicle group, and endorsement request.

Source: FMCSA

A clear preparation plan has three lists: knowledge tests, endorsement tests, and practical driving steps. Use the state agency's instructions to fill each list. Keep each test's appointment, requirements, and study topics together so that a general knowledge review does not hide an endorsement gap.

Plan a focused review

Begin with the vehicle group and endorsements on your application. Read the matching state handbook sections. Build short practice sets for one topic at a time, then mix topics after you understand them. For every wrong answer, find the underlying rule or safe procedure and explain it in a short sentence.

Before the appointment, check the agency page again for current test count, identification, fees, and scheduling details. Federal rules define minimum standards, but state testing procedures can include additional state-specific information. A practice score helps guide study. It does not guarantee a result on the state test.

Source: FMCSA