Checked against official Iowa sources on Oct 7, 2026
Iowa CDL practice test
Every state needs at least 80% on each CDL written test, and Iowa follows the same federal rule. Below are the fees, ages and rules we checked against the official Iowa source, and a free practice test.
FirstTry CDL is not affiliated with any DMV, FMCSA or government agency. Practice questions are exam-style questions built from the official CDL manual, not actual test questions.
Iowa CDL facts
| What | What Iowa says | Source |
|---|---|---|
| Minimum age | You must be at least age 18 to get a CDL | Official page |
| CLP fee | $12. The permit is valid for one year | Official page |
| CLP validity | One year from the date of issue, with no renewal period | Official page |
| CLP holding period | Hold the CLP for at least 14 days before the skills and drive test | Official page |
| CDL fee | Class A, B or C commercial license: $8 per year, for 8 years | Official page |
| Endorsement fees | Doubles/triples $5. Passenger $10. Tank $5. Hazmat $5. School bus $10. Hazmat and tank together $10 | Official page |
| Hazmat endorsement fee at renewal | The hazmat fee is charged at each renewal. Other endorsement fees are charged one time | Official page |
| Restriction removal fees | Removing the air brake, full air brake, manual transmission or tractor-trailer restriction: $10 each | Official page |
| General knowledge test | 50 questions. You may miss 10 | Official page |
| Endorsement test lengths | Combination 20 (miss 4). Air brake 25 (miss 5). Passenger 20 (miss 4). School bus 20 (miss 4). Doubles/triples 20 (miss 4). Tank 20 (miss 4). Hazmat 30 (miss 6) | Official page |
| Iowa operator test | If you need it, the Iowa operator test is 25 questions. You may miss 5 | Official page |
| Skills test retest | If you fail the air brake check or pre-trip inspection, you must make another appointment. Iowa DOT says that could be two or three weeks out | Official page |
| Skills test parts | Three phases: pre-trip vehicle inspection, basic vehicle control (cones and backing), and driving on public roads with an examiner | Official page |
| Air brake check | You must show every part of the air brake check before you start the pre-trip inspection test | Official page |
| ELDT | Entry-Level Driver Training is required before the skills and drive test for a first Class A or B CDL, a Class B to Class A upgrade, or a first P, S or H endorsement. Iowa checks it electronically before the skills test | Official page |
| Where tests are given | Knowledge and skills tests are given at DOT driver's license service centers, select county treasurer locations, or third-party testers | Official page |
| Third-party testers | Their tests are identical to DOT tests, but they may charge fees or require class enrollment. You still make an appointment at a service center to get your CDL | Official page |
| Interstate record check | Iowa runs an interstate driving record check on every CDL applicant. It must show you are eligible for commercial licensing in all other states | Official page |
| Medical certification | All CDL holders must certify how they use commercial vehicles, which may require a medical certificate from an examiner on the National Registry | Official page |
| Hazmat security check | For a hazmat endorsement you need a valid TSA Security Threat Assessment. The Iowa DOT does not run that program | Official page |
| Online practice | Iowa has a free CDL test app with over 600 practice questions. It also has a web version | Official page |
Fees and rules change. Confirm on the official Iowa CDL page before you go. Read the official Iowa CDL manual.
CDL test formats
We show the national defaults for question counts and time limits. Check the official Iowa manual for anything that differs.
| Test | Questions | To pass | Typical time |
|---|---|---|---|
| General Knowledge | 50 | 40 (80%) | About 60 minutes |
| Air Brakes | 25 | 20 (80%) | 25 to 30 minutes |
| Combination Vehicles | 20 (25 questions in some states) | 16 (80%) | 20 to 25 minutes |
| Hazardous Materials | 30 | 24 (80%) | 30 to 40 minutes |
| Tanker | 20 | 16 (80%) | 20 to 25 minutes |
| Passenger | 20 | 16 (80%) | 20 to 25 minutes |
| School Bus | 20 (25 questions in some states) | 16 (80%) | About 25 minutes |
| Doubles/Triples | 20 | 16 (80%) | About 20 minutes |
Practice any of them: all CDL practice tests.