DMV-Written-Test helps aspiring commercial drivers in Iowa prepare with accurate practice exams based on the 2025 Iowa Commercial Driver License (CDL) Manual. These CDL practice tests simulate the actual exam administered by the Iowa Department of Transportation (Iowa DOT).
Whether you’re applying for a Class A, B, or C CDL, our practice tests cover all essential areas including General Knowledge, Air Brakes, Combination Vehicles, and Iowa-specific rules.
For official manuals, licensing info, and CDL test scheduling, visit the Iowa DOT CDL services page: https://iowadot.gov/mvd/cdl
Get started today and pass your Iowa CDL permit test with confidence!
📘 What to Expect on the Iowa CDL Knowledge Test
Aspect
Details
Number of Questions
50 (General Knowledge)
Passing Score
80% (40 correct answers required)
Test Format
Multiple Choice
Time Limit
60 minutes (approx.)
Minimum Age
18 (21 for interstate driving or HazMat)
Test Languages
English, Spanish, others (availability varies)
Endorsement Areas
Air Brakes, Tankers, Passenger, HazMat, School Bus
Retake Policy
May retake next business day (retest fee may apply)
❓ Frequently Asked Questions
How do I qualify for a CDL permit in Iowa?
You must be at least 18 years old, hold a valid Iowa Class D license, and pass the CDL General Knowledge test and vision screening.
Is ELDT required before taking the skills test?
Yes. Entry-Level Driver Training (ELDT) is mandatory for first-time CDL applicants and certain upgrades or endorsements.
How long is the Iowa CDL permit valid?
The Commercial Learner’s Permit (CLP) in Iowa is valid for 180 days and may be renewed once.
Can I take the CDL test in Spanish?
Yes. The knowledge test is available in Spanish. The HazMat test is only available in English.
What happens if I fail the written test?
You may retake the CDL knowledge test the next business day. Additional fees may apply.
Do I need an Iowa license before applying?
Yes. A valid Iowa Class D driver’s license is required to apply for a CDL permit.
Do endorsements require additional testing?
Yes. Endorsements like HazMat, School Bus, or Tanker require separate written exams.
Can I transfer a CDL from another state to Iowa?
Yes. You must transfer your CDL within 30 days of establishing residency in Iowa.
What documents are required for an Iowa CDL?
Proof of identity, Iowa residency, Social Security number, and lawful presence are required.
Do I need TSA clearance for a HazMat endorsement?
Yes. You must pass a TSA background check to obtain or renew a HazMat endorsement.
