The CDL Knowledge Test in 2027

What the knowledge test covers

49 CFR 383.133 requires every state to use FMCSA’s pre-approved pool of questions to develop knowledge tests for each vehicle group and endorsement. The pool must be comparable to the AAMVA test-item summaries FMCSA has approved and provides to state driver licensing agencies. Each test must contain a set number of questions, with a prescribed number from each knowledge area. The regulation does not print that number in the section itself.

States build a knowledge test for each vehicle group and endorsement from that pool. Air brakes and combination vehicles are separate portions. 49 CFR 383.135 attaches an air-brake restriction when the air-brake portion is failed, and it blocks a Group A credential when the combination portion is failed. Your state manual is the list of tests that applies to you.

Sources: 49 CFR 383.133: Test methods; 49 CFR 383.135: Passing knowledge and skills tests

The 80 percent rule

49 CFR 383.135 says that to pass each knowledge test, an applicant must correctly answer at least 80 percent of the questions. Two consequences are in the same section. An applicant who scores under 80 percent on the air-brake portion, and who is still issued a CLP or CDL, must have an air-brake restriction on that credential. An applicant who fails the combination-vehicle portion must not be issued a Group A CLP or CDL.

The skills-test passing standard in that section is different. It points to the scores in the examiner manual for the vehicle used in the test, and it lists automatic-failure conditions such as disobeying traffic laws or causing an accident during the test. This page is about the knowledge test. The skills-test order is covered in how to get a CDL in 2027.

Sources: 49 CFR 383.135: Passing knowledge and skills tests

Question counts are state examples

California’s current commercial driver license page says you have three attempts to pass each required knowledge test. If you fail the same test three times, the application is no longer valid and you reapply. That page does not publish how many questions are on each test.

The question totals below are Table 1 of California DMV’s March 2008 statewide evaluation of the written tests then in use, forms DL 653, 654, and 655, Rev. 10/2006. The report says those are the number of questions and the maximum number an applicant could miss and still pass, for the forms in that evaluation. Treat the table as a 2008 California record, not as the 2027 form.

Pennsylvania’s CDL learner’s-permit FAQs describe a different limit: a Knowledge Test Authorization is valid for one year from issuance and gives three tries on that authorization to pass the knowledge tests.

New York DMV’s get-a-CDL page, in the August 30, 2026 capture, does not publish a General Knowledge question count or a “number correct” passing line. It does publish the $10 application fee for written tests taken together. Fee details are on the how-to-get-a-CDL page.

Sources: California DMV: Commercial driver licenses; California DMV: Statewide evaluation of CDL written knowledge tests (March 2008); Pennsylvania DMV: CDL learner's permit FAQs; New York DMV: Get a commercial driver license

Retakes use a different version

49 CFR 383.133 says a state must use a different version of the test when an applicant retakes a previously failed test. The same section says the state’s method of generating tests must put identical questions from the previous version in a different location, with the three responses in a different order, and that 25 percent of the questions on a test must be new questions that were not on the previous version.

A practice set you repeat on this website is not that official retake version. Review the idea you missed instead of memorizing the answer position.

Sources: 49 CFR 383.133: Test methods

Language rules differ by state

49 CFR 383.133 says knowledge tests may be given in written, verbal, or automated form, and can be administered in a foreign language, provided no interpreter is used. The skills test is not included in that option. Interpreters are prohibited, and the skills test is conducted in English.

Texas DPS states that, effective June 1, 2026, it will exclusively administer all CDL knowledge examinations in English, and that Spanish-language versions of the CDL knowledge tests will no longer be offered.

The August 30, 2026 copy of New York DMV’s get-a-CDL page says the written tests for CDL Class A, Class B, and Class C and endorsements are available in English, Spanish, Chinese, and Russian only, and that the hazardous materials endorsement test is available in English only.

Sources: 49 CFR 383.133: Test methods; Texas DPS: How to apply for a commercial driver license; New York DMV: Get a commercial driver license

Practice tests on this site

These eight practice tests follow the standard manual subjects. They are original study questions, not the FMCSA pool and not your state’s current form. For the app, see features and pricing or the 2027 practice-app comparison.

• General Knowledge practice test
• Air Brakes practice test
• Combination Vehicles practice test
• HazMat practice test
• Tank Vehicles practice test
• Doubles/Triples practice test
• Passenger practice test
• School Bus practice test

State pages combine the official manual link, these practice tests, and registered schools: California, Texas, New York, Pennsylvania.

Sources and editorial notes

Editorial attribution: Evergreen Comply, LLC Editorial Staff. Each section links the official page the statement comes from. These pages do not replace your state manual, a registered training provider, or instructions from your licensing agency.

• 49 CFR 383.133: Test methods
  FMCSA question pool. Knowledge tests may be in a foreign language without an interpreter. A retake uses a different version. Skills tests are in English, in order: pre-trip inspection, basic vehicle control, on-road skills.
• 49 CFR 383.135: Passing knowledge and skills tests
  At least 80 percent on each knowledge test. Failing air brakes requires an air-brake restriction if a CLP or CDL is issued. Failing the combination-vehicle test blocks a Group A CLP or CDL.
• California DMV: Commercial driver licenses
  CLP steps include MCSA-5875 and MCSA-5876, a 14-day hold, three knowledge-test attempts, and an application valid for 12 months. The page also says California has paused non-domiciled CLP and CDL issuance until further notice.
• California DMV: Statewide evaluation of CDL written knowledge tests (March 2008)
  March 2008 evaluation of forms DL 653, 654, and 655, Rev. 10/2006. Table 1 lists question counts and allowed errors for those forms. It is not a 2027 test specification.
• Pennsylvania DMV: CDL learner's permit FAQs
  A Knowledge Test Authorization is valid for one year from issuance and allows three tries on that authorization to pass the knowledge tests.
• Texas DPS: How to apply for a commercial driver license
  Effective June 1, 2026, Texas administers CDL knowledge examinations in English only. The page lists the knowledge-test order and a 14-day CLP hold before skills tests.
• New York DMV: Get a commercial driver license
  Application fee $10 for written tests taken together; additional $5 for a required test not taken and passed then; road test fee $40. Checked October 26, 2026 against the Internet Archive capture dated August 30, 2026. That page does not publish a General Knowledge question count. The live page returned a bot check on October 26, 2026.

Last reviewed October 26, 2026. Next source review due January 26, 2027, or earlier if the official guidance changes.

Related pages

• How to get a CDL in 2027
• CDL rule changes heading into 2027
• CDL manual by state
• Best CDL practice test apps for 2027
• CDL Prep Hero app