An electrician from Duluth shows up for the Class A journeyworker exam with a code book full of color-coded tabs. They have practiced flipping to Article 310 in seconds. At the door, the proctor explains that nothing comes in. The Minnesota Department of Labor and Industry hands every candidate a clean, soft-cover code book with no tabs, a laws and rules booklet and a desk calculator. The tabs stay in the truck.
Here is the plain answer. Minnesota runs its own electrical, plumbing and residential contractor exams through the Department of Labor and Industry (DLI), not a testing company. For the electrical and residential exams, the department provides the reference books in the room. Electrical, plumbing and residential building exams all have a 5.5-hour time limit, and the electrical and residential exams need 70 percent to pass.
The detail that matters most: you cannot count on your own books or your own tabs. DLI’s electrical guide says most questions are meant to be answered without looking anything up.
The exams at a glance
- Class A Journeyworker Electrician: 80 questions, 5.5 hours, 70 percent (56 correct).
- Class A Master Electrician: 80 questions, 5.5 hours, 70 percent (56 correct).
- Journeyworker Plumber: 80 questions, 5.5 hours, 70 percent.
- Master Plumber: 100 questions, 5.5 hours, 70 percent.
- Qualifying Builder (residential building contractor): 110 questions, 5.5 hours, 70 percent.
- Qualifying Remodeler: 110 questions, 5.5 hours, 70 percent.
The time limits come from DLI’s license exam schedule page, which lists 5.5 hours for all electrical exams, all plumbing exams, and the residential building contractor, remodeler and roofer exams. The electrical figures come from DLI’s electrical license examination guide. The residential figures come from DLI’s contractor, roofer and remodeler exam page. All were read today.
Electrical: the code book is theirs, not yours
The electrical guide is unusually detailed about how the exam works. The points that change how you study:
- Code edition. Questions use the 2026 National Electrical Code, which became effective in Minnesota on August 17, 2026. The current exam format has been in effect since September 8, 2026.
- What is in the room. DLI provides a soft-cover NEC with no tabs or other aids, a Laws and Rules Booklet and a common desk calculator. No other materials or electronic devices are allowed in the building.
- How much you can look up. The guide says the majority of questions are intended to be answered without referring to the reference materials.
- No notes. Copying questions or making notes about them is an automatic fail.
- Question style. Wrong answers are written to be plausible. Some questions include extra information you do not need. A few use a “does NOT apply” format.
Master vs journeyworker
Both are 80 questions on the same clock. The difference is difficulty. DLI rates each question from 1 to 5. The master exam is set at an average difficulty of 2.5 to 3.5, because a master can be the responsible licensed person for an employer. The journeyworker exam is set at 1.5 to 2.5.
The guide says the hardest questions apply several code rules at once or need multiple calculations. Its sample section is worth working by hand: Ohm’s law, series and parallel circuits, three-phase power, voltage drop and transformer current, plus a sample motor feeder question.
Our Minnesota Journeyworker Electrician exam prep is built on this format.
Plumbing: a long clock and the state code
The journeyworker plumber exam is 80 questions and the master plumber exam is 100. DLI lists 5.5 hours for all plumbing exams, and both need 70 percent.
The code is the Minnesota Plumbing Code, Minnesota Rules chapter 4714. It is based on the Uniform Plumbing Code with Minnesota amendments, not the International Plumbing Code. If you trained in a state that uses the IPC, the section numbers and some of the rules will not match what you know.
Eligibility comes before the exam, and DLI’s plumbing experience requirements page is specific about it:
- Journeyworker: at least four years of recorded practical experience as a DLI-registered unlicensed plumber, or a completed DLI-registered apprenticeship, among other routes. A year of experience is at least 1,750 hours, and no more than 1,750 hours count in one calendar year.
- Master: at least one year of practical experience as a licensed journeyworker plumber, or an equivalent license from another state.
- Who signs: experience must be certified by the licensed master plumber responsible for the work.
See our Minnesota Journeyworker Plumber exam prep.
Residential builder and remodeler
These are separate licenses with separate exams. A company’s qualifying person takes the qualifying builder (QB) exam for a residential building contractor license, or the qualifying remodeler (QC) exam for a residential remodeler license. A building contractor license covers everything a remodeler can do, plus new construction.
- Length: 110 multiple-choice questions in 5.5 hours, 70 percent to pass.
- Content: roughly 60 percent of the questions come from the Minnesota Residential Building Code. The rest cover the statutes and rules for the residential construction industry.
- Books in the room: DLI provides the 2020 Minnesota State Residential Code and the DLI Reference Manual for the Residential Building Contractor and Remodeler License Exam.
- Prerequisites: none. There are no experience or education requirements to sit the residential exams.
- Language: the qualifying builder exam is available in English and Spanish.
The statutes and rules share is the part trade-experienced builders underestimate. Lien rights, contract requirements and licensing rules do not come from swinging a hammer. Our Minnesota Residential Building Contractor exam prep covers both halves.
Results and retakes
- Electrical results are emailed, generally within two weeks. They are not given by phone. Reviews of individual exams are not available.
- Electrical retakes: you may apply to retake 30 days after you are notified of the fail.
- Plumbing retakes: DLI says you must wait 30 days before reapplying.
- Residential retakes: wait 30 days, then submit a new application and fee.
Thirty days is short compared with many states. It is still a month, plus a new application, so going in ready matters.
How to prepare for a state-run exam
- Study to answer without the book. DLI says that is how most electrical questions are designed. Use the book for confirmation, not discovery.
- Practice on a clean, untabbed code book. That is what you get on exam day. Learn the index and the article order.
- Use the right edition. 2026 NEC for electrical. The Minnesota Plumbing Code for plumbing. The 2020 Minnesota State Residential Code for builders.
- Work calculations with a basic calculator. The one provided is a common desk type.
- Give the laws and rules real time. Every one of these exams includes Minnesota-specific statutes and rules.
Questions candidates ask
Can I bring my own tabbed NEC to the Minnesota electrical exam?
No. DLI provides the code book and the guide says no other materials are allowed in the building.
Is the Minnesota plumbing exam based on the IPC?
No. Minnesota’s plumbing code, chapter 4714, is based on the Uniform Plumbing Code with state amendments.
Where do these numbers come from?
The time limits, electrical and residential figures are from the DLI pages linked above. DLI’s public pages do not list the plumbing question counts; those come from our own exam facts records. Our page on how we source our exam facts explains the process.
Next step
Find your license on our Minnesota exam prep page. Each course is built for a state-run exam with the books provided.