Free Iowa CDL Practice Tests — Your Complete Study Guide
Pass your Iowa CDL permit exam with 80%+ on the first try
Updated: August 2026
What You Need to Study
General Knowledge
The foundation of your CDL exam. Covers traffic laws, safe driving techniques, vehicle inspection procedures, cargo handling, and federal regulations every commercial driver must understand.
Combination Vehicles
Essential for driving tractor-trailers. Covers coupling and uncoupling procedures, rollover prevention, inspecting combination vehicles, and safely maneuvering with attached trailers.
Air Brakes
Required for any vehicle equipped with air brakes. Covers how air brake systems work, dual air brake systems, inspecting air brakes, and using them safely in all conditions.
Endorsement Tests
HazMat
Required for transporting hazardous materials. Covers placarding, labeling, loading procedures, emergency response, and compliance with federal hazmat regulations.
Tanker
Required for driving tank vehicles used to transport liquids or gases in bulk. Covers safe loading, unloading, and driving techniques specific to tanker operations.
Doubles & Triples
Required for pulling double or triple trailers. Covers coupling and uncoupling multiple trailers, safe driving practices, and inspection procedures for multi-trailer rigs.
Passenger
Required for operating vehicles designed to transport 16 or more passengers. Covers passenger safety, loading, emergency exits, and pre-trip inspection requirements.
Free Iowa CDL Practice Tests — Your Complete Study Guide
What should you do when merging?
- Merge at a much lower speed than the flow of traffic.
- Use your mirrors to make sure the gap in traffic is large enough for you to enter safely.
- Merge without signaling.
Documents related to hazardous materials transportation must be stored ___.
- In the pouch of the driver door.
- Attached to the sun visor.
- In a box on the trailer.
Which of these statements about driving through a tunnel is correct?
- Keep windows open for fresh air.
- Turn off all lights inside the truck.
- There may be strong winds when exiting.
Among these vehicles, which is more likely to experience off-tracking during turns?
- Tractor with 45-feet trailer.
- 28-feet box truck
- 45-feet straight truck
Under what circumstances should you sound your horn?
- If it helps to avoid a crash.
- To let others know you are running late.
- To say hello to a friend on the sidewalk.
Identify the incorrect statement regarding alcohol consumption.
- A drinker can control how fast his or her body absorbs alcohol.
- Alcohol goes directly from the stomach to the blood stream.
- BAC is determined by how fast you drink; how much you drink and how much you eat.
If your vehicle is missing ____ or more leaves from any leaf spring, it won't be allowed to be used.
- 1/3
- 1/4
- 1/2
Select the correct statement regarding the transportation of hazardous materials.
- Any truck carrying any amount of hazardous materials must have placards.
- Hazardous materials can be disposed of in regular trash bins if the containers are sealed.
- All hazardous materials present health and safety danger.
To figure out how much alcohol is in someone's blood (BAC), you need to know:
- Their height.
- The time of day they drink alcohol
- Their weight.
What is the right way to hold a steering wheel?
- With one hand on the top of the wheel and the other on your lap.
- With your knees, while using your hands to adjust the radio.
- With both hands, on opposite sides of the wheel.
What Are You Preparing For?
Select one or more options so we can show you exactly which tests you need to take.
What You Need to Study
General Knowledge
16 sections · 800 questions
The foundation of your CDL exam. Covers traffic laws, safe driving techniques, vehicle inspection procedures, cargo handling, and federal regulations every commercial driver must understand.
Combination Vehicles
9 sections · 180 questions
Essential for driving tractor-trailers. Covers coupling and uncoupling procedures, rollover prevention, inspecting combination vehicles, and safely maneuvering with attached trailers.
Air Brakes
6 sections · 150 questions
Required for any vehicle equipped with air brakes. Covers how air brake systems work, dual air brake systems, inspecting air brakes, and using them safely in all conditions.
Endorsement Tests
Additional endorsements you may need depending on the type of vehicle or cargo you plan to operate.
HazMat
9 sections · 202 questions
Required for transporting hazardous materials. Covers placarding, labeling, loading procedures, emergency response, and compliance with federal hazmat regulations.
Tanker
6 sections · 133 questions
Required for driving tank vehicles used to transport liquids or gases in bulk. Covers safe loading, unloading, and driving techniques specific to tanker operations.
Doubles & Triples
7 sections · 144 questions
Required for pulling double or triple trailers. Covers coupling and uncoupling multiple trailers, safe driving practices, and inspection procedures for multi-trailer rigs.
Passenger
6 sections · 123 questions
Required for operating vehicles designed to transport 16 or more passengers. Covers passenger safety, loading, emergency exits, and pre-trip inspection requirements.
Your Path to a Commercial Driver's License
To get a CDL, you must first study for and pass the permit exam at the DMV. After you receive your permit, you can take commercial vehicle driving classes and complete the required training. The final step is passing the official driving exam to earn your CDL. Our practice tests help you prepare for the DMV permit exam with real-style questions, and we also provide extra study materials and helpful resources to guide you through the process.
To obtain a CDL in Iowa, you must pass the written permit tests that match your license class — General Knowledge for everyone, plus Combination Vehicles and Air Brakes where they apply — at the Iowa Department of Motor Vehicles. Similar to a regular driver's license permit exam, these are timed, multiple-choice tests based on the official Iowa CDL handbook.
All of our practice material is built from the official Iowa CDL handbook and federal resources, and curated by professionals with over 10 years of experience in the commercial transportation industry. Studying with practice tests that mirror the real exam format is one of the most effective ways to pass on your first try.
On this page you'll find free practice tests for all three sections. All 2,500+ questions and the study tools are in the app with a subscription — download the CDL Help app.
Iowa CDL Knowledge Test: Format & Requirements
The CDL knowledge (written) test follows the same federal standards in Iowa as nationwide. Here's what to expect.
Questions by test
The 80% passing score is a federal standard (FMCSA, 49 CFR 383.135). Question counts follow the AAMVA model used by most states and can vary by state. Always confirm current details with your state's official CDL handbook.
Iowa CDL Fees & Licensing
$8/yr × 8 years
State-charged fees as of June 2026. Amounts change — confirm current fees with the official agency.
CDL Requirements in Iowa
iowadotiowadotiowadot49 CFR §391.11
- Citizenship and immigration-status requirements apply and changed under 2026 federal rules — verify your eligibility directly with the Iowa Department of Transportation (Iowa DOT) before applying (see Official Sources below).
- Must be at least 18 years old for an Iowa CDL; 21 to drive a commercial motor vehicle in interstate travel.
- Pass a vision screening and an interstate driving-record check — Iowa DOT runs the record check on every CDL applicant to confirm you are eligible for commercial licensing in every other state.
- Provide proof of Iowa residency: your Iowa license showing your address, or two proofs if you do not already hold one.
- Iowa prorates the license fee against the term: $8 per year of a Class A, B or C commercial license, with an 8-year term standard ($64 in total) and a 2-year term once you turn 78.
- Book a knowledge-test appointment at any Iowa DOT or county treasurer location (third-party testers also give the tests, and may charge their own fee).
- Pass the knowledge test for the vehicle you want: general knowledge is 50 questions (10 allowed misses), plus combination (20/4) for Class A and air brake (25/5) as they apply.
- Pay $12 for the Commercial Learner’s Permit, added to your existing Iowa license and valid for one year with no renewal — hold it at least 14 days and complete Entry-Level Driver Training before the skills and drive test.
- Entry-Level Driver Training is required for a first Class A or B CDL, for CDL upgrades, and for the Hazmat, Passenger and School Bus endorsements; Iowa DOT confirms your record on the FMCSA Training Provider Registry before testing you.
- Pass the three-phase skills and drive test — pre-trip vehicle inspection (the air-brake check must be demonstrated in full first), basic control skills, and the on-road drive — in a vehicle you supply.
- Every CDL holder self-certifies one of four driving categories (non-excepted or excepted, interstate or intrastate); certifying an intrastate category adds a “K” restriction to the license.
- Since October 23, 2025, CDL medical certificates are digital in Iowa — your examiner on the National Registry of Certified Medical Examiners files it electronically.
- Non-citizens who are not lawful permanent residents, or citizens of Canada or Mexico, present an unexpired foreign passport plus an I-94 showing an eligible status; an Employment Authorization Document is no longer accepted.
- An expired CDL is still valid for driving in Iowa for 60 days past the expiration date; after one year expired you retake the knowledge and driving tests.
Official Iowa CDL Handbook
The official Iowa Commercial Driver's License Manual covers every topic tested on the state's CDL knowledge exam — but it reads like a dense reference manual, not a structured study guide. A more effective way to prepare is with our General Knowledge practice tests. Our free Iowa CDL permit practice test mirrors the format and content of the official exam and is fully up to date as of February 2026. Each practice test features 20 questions covering essential topics such as vehicle inspection, safe driving techniques, air brakes, cargo securement, driving emergencies, hazardous conditions, and Iowa-specific commercial driving regulations. Unlike the official test, every practice question comes with a helpful hint and a detailed explanation of the correct answer — so you actually learn from every question you answer.
- Complete CDL regulations and Iowa-specific requirements
- Safe driving techniques, vehicle inspection, and cargo handling
- All endorsement categories and testing requirements
CDL Practice Tests in Nearby States
Testing near Iowa? Practice for a neighboring state's CDL exam too.
Non-Domiciled CDL Information
Important information about non-domiciled commercial driver's licenses in Iowa.
Federal regulations on non-domiciled CDLs are changing rapidly. The information below reflects the latest known state actions.
Iowa DOT states its non-domiciled CDL process directly on its Get a CDL page: individuals who are not U.S. citizens, lawful permanent residents, or citizens of Canada or Mexico may present an unexpired foreign passport together with an I-94 showing a future “valid until” date and an eligible classification. An Employment Authorization Document is no longer accepted as proof for issuing a non-domiciled CLP or CDL, and citizens of Mexico or Canada cannot obtain or renew one at all, per 49 CFR 383.71 and 383.23.
Under the FMCSA final rule published February 13, 2026 (effective March 16, 2026), eligibility for a foreign-domiciled CLP or CDL nationwide is limited to H-2A, H-2B and E-2 status. Iowa DOT’s own document list already matches this narrower federal standard. CDL Help does not provide legal or immigration advice, and these requirements are changing quickly — confirm your specific situation directly with the Iowa DOT and the official FMCSA resources linked below.[FMCSA Final Rule]
English Language Proficiency (ELP)
Federal ELP enforcement applies to all CDL holders nationwide.
Federal ELP enforcement applies to all CDL holders nationwide. Here is how it is enforced in Iowa.
Iowa does not currently administer a separate state-level English Language Proficiency (ELP) test for CDL applicants. However, all Iowa CDL holders are subject to federal ELP enforcement, which took effect on June 25, 2025. Under this enforcement, roadside inspectors conduct a two-step assessment: first, a conversational interview in English — no interpreters or translation tools are permitted — to evaluate whether the driver can communicate sufficiently in English; second, the driver must demonstrate the ability to read and interpret standard U.S. traffic signs. Drivers who fail either step of the assessment are placed out of service under CVSA guidelines. Iowa CDL applicants should be prepared to demonstrate English proficiency during any roadside inspection or compliance review.
Iowa CDL facts
| Fact | Value | Source |
|---|---|---|
| Commercial learner’s permit (CLP) | $12Flat fee, not prorated; must be added to an existing Iowa license | iowadot.gov |
| Commercial license (Class A, B or C) | $8 per year of the license termStandard term is 8 years, so a full-term CDL is $64; drivers 78 and over get a 2-year term ($16) | iowadot.gov |
| Commercial license term | 8 yearsLicenses issued to people 78 and over are valid for two years | iowadot.gov |
| Upgrading a non-commercial license to a CDL | $4 per year, with the existing license proratedThe new credential runs to the existing license’s expiry | iowadot.gov |
| Tank vehicle (N) endorsement fee | $5 | iowadot.gov |
| Double/triple trailers (T) endorsement fee | $5 | iowadot.gov |
| Passenger (P) endorsement fee | $10 | iowadot.gov |
| School bus (S) endorsement fee | $10 | iowadot.gov |
| Card reprint when an endorsement is added off-cycle | $10Charged on top of the endorsement fee if you add it outside your regular renewal period | iowadot.gov |
| Removing a CDL restriction | $10 eachAir brake, full air brake, manual transmission and tractor-trailer restrictions; may require a pre-trip inspection or skills and driving test | iowadot.gov |
| Card-payment surcharge | $1.50 when paying by credit cardCounty locations may charge an additional convenience fee | iowadot.gov |
| Out-of-county surcharge | $10 may apply at a county office outside where you liveSet by the county, not the Iowa DOT | iowadot.gov |
| Minimum age | 18 for an Iowa CDL; 21 to drive a commercial motor vehicle in interstate travel | iowadot.gov |
| Vision screening | Required of every CDL applicant | iowadot.gov |
| Interstate driving-record check | Run for every CDL applicant; must show you are eligible for commercial licensing in all other states | iowadot.gov |
| Proof of Iowa residency | Your Iowa license showing your address; two proofs of residency if you do not already hold one | iowadot.gov |
| Non-domiciled CLP/CDL documents | Unexpired foreign passport plus an I-94 showing H-2A, H-2B, E2, CFA/FSM, CFA/MIS, CFA/RMI or CFA/PALAn Employment Authorization Document is no longer accepted; Mexican and Canadian citizens cannot get or renew a non-domiciled CDL (49 CFR 383.71, 383.23) | iowadot.gov |
| Employment Authorization Document (EAD) | No longer acceptable documentation for a non-domiciled CLP or CDL | iowadot.gov |
| Entry-Level Driver Training (ELDT) | Required for a first Class A or B CDL, for CDL upgrades, and for the H, P and S endorsementsIowa DOT confirms your record on the FMCSA Training Provider Registry before it will test you | iowadot.gov |
| The four steps to an Iowa CDL | Knowledge tests → CLP → ELDT → skills and drive test | iowadot.gov |
| General knowledge test | 50You may miss 10 | iowadot.gov |
| Pass mark | Stated as questions you may miss: 10 of 50 (general knowledge), 6 of 30 (hazmat), 5 of 25 (air brake), 4 of 20 (combination, passenger, school bus, doubles/triples, tank) | iowadot.gov |
| Air brake knowledge test | 25You may miss 5 | iowadot.gov |
| Combination vehicle test (Class A) | 20You may miss 4 | iowadot.gov |
| Where to take the knowledge test | Any Iowa DOT DMV or county treasurer location, by appointmentMore sites are listed on the CDL Testing Locations page | iowadot.gov |
| Skills and drive test vehicle | You supply it: validly registered, in good working order and representative of the class you are applying for | iowadot.gov |
| Skills and drive test format | Three phases: pre-trip vehicle inspection, basic control skills (cones and backing), and the on-road driving test | iowadot.gov |
| Air-brake check | Must be demonstrated in full before the pre-trip vehicle inspection test begins (section 11 of the CDL Manual) | iowadot.gov |
| If you fail the air-brake check or pre-trip inspection | Make another appointment — Iowa DOT warns it could be two or three weeks out | iowadot.gov |
| Third-party testers | Companies authorized and trained by the Iowa DOT give identical tests, but may charge their own fees or require class enrollmentGoverned by 49 CFR and Iowa administrative rule 761—607.30(321) | iowadot.gov |
| CLP validity | One year from the date of issuance, with no renewal period | iowadot.gov |
| Minimum CLP holding period | 14 daysELDT must also be satisfied before the skills and drive test | iowadot.gov |
| When you need a CLP | A first CDL, a return after a year without one, or an upgrade that needs a skills test | iowadot.gov |
| Self-certification | Four categories — non-excepted interstate, excepted interstate, non-excepted intrastate, excepted intrastate — chosen every time you receive a CDL product | iowadot.gov |
| Medical certificates | Digital in Iowa — your examiner submits the certificate electronicallyeffective October 23, 2025 | iowadot.gov |
| Who can do the DOT physical | A doctor active on the National Registry of Certified Medical Examiners | iowadot.gov |
| Intrastate-only restriction | K — added to the CDL when you self-certify to an intrastate category | iowadot.gov |
| Expired CDL | Valid for driving in Iowa 60 days past expiry; after one year you must retake the knowledge and driving tests | iowadot.gov |
| Where to renew | Any of Iowa’s 100 issuance sites, or online if you meet the eligibility rulesOnline renewal adds a $1.50 processing fee and is not available with an H or X endorsement | iowadot.gov |
| Licensing agency | Iowa Department of Transportation (Iowa DOT), Motor Vehicle Division | iowadot.gov |
| Farm-service alternative to the H endorsement | A restricted CDL covers liquid fertilizers (3,000 gallons or less) and solid fertilizers for farm-related service industries, with no CDL knowledge or driving testValid up to 210 days a calendar year, within 150 miles of the place of business | iowadot.gov |
| Restricted CDL testing | No CDL knowledge or driving test is required to be issued a restricted CDLInstead you need two years of unaccompanied driving experience and a clean two-year record | iowadot.gov |
| Restricted CDL validity | Up to 210 days per calendar year, taken together or split into at most three periods | iowadot.gov |
How to get a CDL in Iowa
- Check you are eligible: at least 18 years old (21 to drive in interstate commerce), able to pass the vision screening, and able to pass the interstate driving-record check every Iowa CDL applicant goes through. Source
- Gather your documents — proof of full name, date of birth and Social Security number, proof of citizenship or lawful presence, and proof of Iowa residency (two proofs if you do not already hold an Iowa license). Source
- Book a knowledge-test appointment at any Iowa DOT DMV or county treasurer location (third-party testers also give the tests, but may charge their own fee). Source
- Pass the knowledge tests for the vehicle you want to drive: general knowledge is 50 questions with 10 allowed misses, plus combination (20/4) for Class A, air brake (25/5) and any endorsement tests. Source
- Pay $12 for the commercial learner’s permit, which is added to your existing Iowa license and is valid for one year with no renewal period. Source
- Complete Entry-Level Driver Training with a provider on the FMCSA Training Provider Registry — Iowa DOT confirms your ELDT record before it will administer the skills test. Source
- Hold the CLP at least 14 days, then book the skills and drive test and bring a registered, road-worthy vehicle representative of the class you are applying for. Source
- Pass the three-phase test: pre-trip vehicle inspection (the air-brake check must be demonstrated first), the basic-control skills test around cones, and the on-road driving test. Source
- Pay the license fee — $8 per year of the term for a Class A, B or C commercial license, normally issued for 8 years ($64), and self-certify the type of commercial driving you do. Source
Official Iowa Department of Transportation (Iowa DOT), Motor Vehicle Division links
- Iowa DOT: Commercial Drivers
- Iowa DOT: How to Get a CDL
- Iowa DOT: Driver's License Fees
- Iowa DOT: CDL Testing
- Iowa DOT: CDL Testing Locations
- Iowa DOT: Schedule an Appointment
- Iowa DOT: Hazardous Materials endorsement
- Iowa CDL Manual (PDF)
- Iowa DOT: Entry Level Driver Training
- Iowa DOT: Commercial Learner Permits (CLP)
- Iowa DOT: Medical Cards & Certification
As of September 2, 2026, verified against Iowa Department of Transportation (Iowa DOT), Motor Vehicle Division.
Iowa CDL questions
- How much does an Iowa CDL cost?
- Iowa charges by the year, not a flat price. A Class A, B or C commercial license is $8 for each year of its term, and the standard term is 8 years — $64 in total, or $16 if you are 78 or over and get a 2-year card. The commercial learner’s permit is a flat $12 for one year, and upgrading a non-commercial license is $4 a year with the existing license prorated. Add $1.50 if you pay by credit card, and up to $10 at a county office outside where you live. Source
- How long is an Iowa commercial learner’s permit good for?
- The CLP costs $12 and is valid for one year from the date it is issued, with no renewal period — if it lapses you start again. It must be added to an existing Iowa license, you must hold it at least 14 days before the skills and drive test, and only the passenger, school-bus and tank endorsements can go on it. Source
- How many questions are on the Iowa CDL knowledge tests?
- Iowa DOT publishes the count and the number you may miss for each test: general knowledge 50 (miss 10), combination vehicle for Class A 20 (miss 4), air brake 25 (miss 5), hazmat 30 (miss 6), and tank, passenger, school bus and doubles/triples 20 each (miss 4). There is also a 25-question Iowa operator test where it applies. Source
- What is on the Iowa CDL skills and drive test?
- Three phases: the pre-trip vehicle inspection, the basic control skills test (cones and backing maneuvers), and the on-road driving test. You must demonstrate the whole air-brake check before the pre-trip inspection starts, and you supply the test vehicle — registered, road-worthy and representative of the class you want. Fail the air-brake check or the pre-trip and you have to rebook, which Iowa DOT warns can be two or three weeks out. Source
- How old do you have to be to get a CDL in Iowa?
- The minimum age for an Iowa CDL is 18, but you must be 21 to operate a commercial motor vehicle in interstate travel. Under 21 you are limited to driving inside Iowa, and self-certifying to an intrastate category adds a “K” restriction to the license. Source
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