Iowa CDL Written Test — Questions, Cost & Study Tips (2026)

Studying for your Iowa CDL written exam? Here is what applicants typically need to know before visiting Iowa DOT.

How many questions on the Iowa CDL test?

Iowa general knowledge written exams commonly include about 50 multiple-choice questions for the core CDL knowledge test. Endorsements such as air brakes, combination vehicles, hazmat, and passenger are separate written tests if your license class requires them.

PassCDL mirrors this structure: start with general knowledge, then add endorsement practice for the tests you need.

Iowa CDL test cost (approximate)

Written exam fees at Iowa DOT are typically $20–$30 per attempt (varies by office and endorsement). Failing and retesting can cost more than a month of PassCDL Pro — many students prefer unlimited practice before test day.

Iowa study tip

Iowa CDL applicants take knowledge tests at DOT service centers — air brakes endorsement is common for tractor-trailers.

Free IA CDL practice test

Use our Iowa CDL practice test for scored questions and explanations. PassCDL Pro adds full exam simulations, all endorsements, and unlimited retakes.

See also: How many questions on the CDL test? · CDL general knowledge study guide

Educational practice only — not affiliated with Iowa DOT or any state DMV.