Iowa CDL Manual 2026

How to use the Iowa CDL Manual

The Iowa DOT draws its 35-question knowledge test from the Iowa CDL Manual, and you need 80% to pass, which is 28 correct answers. Read the 170 pages once for coverage, then answer practice questions to find the rules that did not stick. Practice tells you what you do not know yet; the CDL Manual is where the rule is actually stated, in the words the state chose.

It is also the only source that settles an argument. When a practice answer and your instinct disagree, the Iowa CDL Manual decides it, and every explanation we write points back into it.

What is inside the Iowa CDL Manual

The Iowa CDL Manual runs to 170 pages. These are the areas it covers that the knowledge test can ask about.

• Vehicle inspection and the pre-trip procedure
• Basic control of a heavy vehicle, including turning and backing
• Shifting, speed management and space management
• Seeing hazards and emergency maneuvers
• Air brakes, if your vehicle has them
• Combination vehicles, coupling and uncoupling
• Cargo loading, weight distribution and securement
• Hazardous materials rules and placarding
• Passenger transport and school bus requirements
• Hours of service, logbooks and driver qualification
• Disqualifications, serious traffic violations and testing

The Iowa knowledge test at a glance

Everything below comes from the Iowa DOT directly. It is what the Iowa CDL Manual is preparing you for.

Questions

35

Passing score

80%

Correct answers needed

28 of 35

Time limit

Time limit not published

Test fee

$8

Minimum age

14 for instruction permit

Can you take it online?

Yes, with conditions

Verified against the Iowa DOT in November 2026.