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Iowa · IA
Iowa CDL
Knowledge Test
Everything you need to pass the Iowa CDL knowledge test. The same FMCSA-standardized questions used across all 50 states.
Total CDL fee
$16
CLP wait
14 days
Min age
18+
To pass
80%
CDL Test Sections
The CDL knowledge test is administered by section. Passing score for all sections is 80%.
✓
General KnowledgeREQUIRED
50 questions · Pass with 40+
A
Air Brakes
25 questions · Pass with 20+
C
Combination Vehicles
20 questions · Pass with 16+
H
Hazardous Materials (HazMat)
30 questions · Pass with 24+
D
Doubles & Triples
20 questions · Pass with 16+
T
Tanker Vehicles
20 questions · Pass with 16+
P
Passenger Transport
20 questions · Pass with 16+
S
School Bus
20 questions · Pass with 16+
What to Know About CDL in Iowa
Iowa CDL fees: approximately $16 total — the lowest CDL fees in the country
Iowa is a major agricultural state — grain, livestock, and farm equipment trucking dominate
Agricultural exemptions for farm operations are widely applicable in Iowa
Iowa's highway system is a major north-south and east-west freight corridor (I-80, I-380)
CDL holders must hold their CLP for at least 14 days before the skills test
Iowa CDL knowledge tests are computerized at Iowa DOT driver's license stations
Legal notice
This information is provided for educational purposes only. Requirements can change. Always verify with Iowa Department of Transportation (DOT) for the most current information.
How to Get Your CDL in Iowa
The steps to earn a commercial driver's license in Iowa, from your DOT medical card to your CDL.
- 1
Get your DOT medical card
Visit a certified medical examiner, pass the DOT physical, and keep the certificate on file with Iowa Department of Transportation (DOT).
- 2
Study and pass the knowledge test
Cover General Knowledge plus any endorsements you need (Air Brakes, Combination, HazMat). Practice every section on Koydo until you're scoring 80%+.
- 3
Get your CLP
Pass the Iowa knowledge test at a Iowa DOT Driver's License Station and pay the ~$8 permit fee to receive your commercial learner's permit.
- 4
Hold your CLP for 14 days
Federal rules require a minimum 14-day wait while you practice driving with a licensed CDL holder.
- 5
Pass the skills test
Schedule the pre-trip inspection, basic control, and road test with Iowa Department of Transportation (DOT) (or an approved third-party tester).
- 6
Get your Iowa CDL
Pay the ~$8 CDL fee and you're licensed to drive commercially.
Iowa CDL — Frequently Asked Questions
How much does a CDL cost in Iowa?
Iowa CDL fees come to about $16 total — roughly $8 for the commercial learner's permit (CLP) and $8 for the CDL itself, paid at Iowa Department of Transportation (DOT). Testing and endorsement fees can add to this, so always confirm current amounts with Iowa Department of Transportation (DOT).
What score do I need to pass the Iowa CDL knowledge test?
You need 80% on each CDL knowledge section. Iowa uses the same FMCSA-standardized question pool as every other state, so General Knowledge, Air Brakes, Combination Vehicles, and the endorsement tests are federally consistent.
How old do I have to be to get a CDL in Iowa?
Iowa issues a CDL at 18 for driving within the state (intrastate) and 21 for driving across state lines (interstate) or hauling hazardous materials.
How long must I hold a CLP before the Iowa skills test?
At least 14 days. You pass the knowledge test first to earn your CLP, hold it for 14 days while practicing with a licensed CDL holder, then take the behind-the-wheel skills test.
Where do I take the CDL written test in Iowa?
At a Iowa DOT Driver's License Station. The knowledge test is computerized. Practice every section on Koydo before you go so you walk in ready.
Is the Koydo CDL practice test accurate for Iowa?
Yes. Koydo's questions follow the FMCSA CDL standard that Iowa tests on, plus state-rule practice — with no ads, and your first 15 questions a day are free.
Ready to get your CDL in Iowa?
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