A Minnesota plumbing license comes from the state Department of Labor and Industry (DLI), not your city, and it’s good statewide. Minnesota licenses the person and the business separately. You hold a personal license as a registered unlicensed plumber, journeyworker, or master. The company that sells plumbing work needs its own plumbing contractor license, with a master plumber on board, a $25,000 bond, and insurance.
Who licenses plumbers in Minnesota
The Minnesota Department of Labor and Industry issues plumbing licenses and runs the exams. The Minnesota Plumbing Board writes the plumbing code and the licensing rules in Minnesota Rules chapter 4716. The law itself is Minnesota Statutes 326B.41 to 326B.59.
Cities can do their own plan review and inspections, but only under an agreement with DLI. Under Minn. Stat. 326B.43, no city can revoke, suspend, or restrict a state plumbing license. You still pull local permits where the city handles them.
Requirements change, so confirm with DLI before you apply or pay a fee. This page is a plain-English guide, not legal advice.
License types
DLI’s license types page lists these:
- Registered unlicensed plumber. The entry level. You work for a licensed contractor under direct supervision while you learn. You can also enter through a DLI registered apprenticeship.
- Journeyworker plumber. Minnesota’s word for journeyman. You work statewide under a master plumber.
- Master plumber. Statewide authority for interior plumbing, plus water service, sanitary sewer, and storm sewer inside property lines.
- Plumbing contractor. The business license. It needs a master plumber as its responsible licensed individual.
- Restricted master and restricted journeyworker. For cities and towns under 5,000 people. Under Minn. Stat. 326B.475, the application windows closed in 2008 and 2009. Nobody new can get one. Existing holders can keep renewing.
- Restricted plumbing contractor. A business that can only contract in communities under 5,000.
- Add-ons. Medical gas certification, backflow prevention tester and rebuilder, certified pipelayer, and water conditioning licenses.
How to become a plumber in Minnesota
Here’s how to become a plumber in MN:
- Step 1: Register as an unlicensed plumber. No experience needed. You must be at least 18 and a W-2 employee of a licensed plumbing contractor, a restricted contractor, or a registered plumbing employer. A licensed journeyworker or master must supervise you at all times. The registration runs July 1 to June 30 and renews every year.
- Step 2: Log 4 years and 7,000 hours. You need at least 2,000 hours of water distribution, 2,000 hours of drain, waste and vent, and 1,000 hours of fixture installation. The rest can be any plumbing work.
- Step 3: Pass the journeyworker exam. A DLI registered apprenticeship also qualifies you, and so does a current out-of-state license from a place that requires 4 years of experience and an exam.
- Step 4: Work 1 year as a journeyworker, then take the master exam. DLI may also accept an out-of-state master license it finds equivalent.
A few rules from Minn. Rules 4716.0020 trip people up:
- One year of experience means at least 1,750 hours. DLI credits no more than 1,750 hours per year, so overtime won’t speed things up.
- No more than two years of out-of-state experience counts, unless you were licensed in that state.
- Up to 24 months of plumbing work from before you registered can count, if you worked in the 12 months right before registering.
- Take the journeyworker exam within two years of finishing your experience. If you don’t, the statute says you can lose those four years, unless DLI grants an extension.
Exams
DLI writes and runs the plumbing exams itself under Minn. Stat. 326B.49. There’s no outside testing company. Here’s what DLI publishes:
- Apply first. Apply online in iMS and pay the $50 application and exam fee. Once you’re approved, DLI emails you scheduling instructions.
- Length. DLI’s exam schedule page says all plumbing exams run 5.5 hours.
- Where. The St. Paul DLI office, usually Tuesday through Thursday. DLI also lists sites in Bemidji, Detroit Lakes, Duluth, Mankato, Moorhead, Rochester, St. Cloud, Virginia, Willmar, and Winona.
- Fail? Wait 30 days, then reapply.
- Code. The 2020 Minnesota Plumbing Code (Minn. Rules 4714) has been in effect since December 17, 2021. It’s based on the 2018 Uniform Plumbing Code with Minnesota changes.
DLI doesn’t publish a passing score, question count, or open-book policy for plumbing exams. Ask them at 651-284-5034 before test day.
Renewal
What DLI and the statute say:
- Journeyworker. Two-year license. Expires December 31 of odd-numbered years.
- Master. Two-year license. The statute says December 31 of even-numbered years. DLI’s basics page lumps it in with odd years. Check your real date in iMS.
- Plumbing contractor. Expires December 31 of odd-numbered years.
- Registered unlicensed plumber. Renews every June 30. You also submit a work experience verification form.
Continuing education. Per DLI’s CE page and Minn. Rules 4716.0205:
- Masters and journeyworkers need 16 hours per two-year license period. At least 8 must cover the State Plumbing Code. The rest can be code, technical plumbing topics, the State Building Code, or the plumbing statutes.
- Registered unlicensed plumbers need 2 hours of code CE each year, done by June 30.
- No carryover. Extra hours don’t roll into the next period.
- Online classes count. Course sponsors report your hours to DLI, but keep your certificates.
- Hold more than one license? Your CE counts for all of them. You only complete the hours for the license with the highest requirement.
Cost
These come from DLI’s basics page, contractor page, and Minn. Stat. 326B.092:
- Unlicensed plumber registration: $14 to start.
- Unlicensed plumber renewal: $19 per DLI’s basics page. DLI’s registration page says $14, so confirm.
- Journeyworker or master exam application: $50, nonrefundable.
- Journeyworker renewal: $53. Late fee $20.
- Master renewal: $93. Late fee $40.
- Plumbing contractor license: $188 to apply and $188 to renew.
- Reciprocity application: $50.
After you pass an exam, DLI sends instructions for paying the first license fee. DLI’s plumbing pages don’t list that first-license amount, so confirm it with them. Contractors also pay for the bond and insurance, and those prices vary.
Reciprocity
Minnesota has plumbing reciprocity with just two states: North Dakota and South Dakota. Per DLI’s reciprocity page, it covers journeyworker and master licenses if:
- You got the license by a state-level exam, not through a city agreement.
- You’ve held it at least one year, and it’s current and in good standing.
- You haven’t failed the same or a higher Minnesota plumbing exam.
- You’re not under an order denying, suspending, or revoking a Minnesota plumber license.
The fee is $50. After approval, you have 180 days to pay the license fee. If your own Minnesota license lapsed more than two years ago, reciprocity is out and you retest.
From another state? Your license may still qualify you to sit for the Minnesota exam. See our plumbing license reciprocity guide for other states.
How to apply
- Go online. Apply for registrations, exams, reciprocity, and contractor licenses in DLI’s iMS system.
- For a contractor license, line up the checklist. Per DLI’s contractor basics page:
- A master plumber as your responsible licensed individual. They must be an owner, officer, member, or W-2 employee, and they can’t serve another contractor.
- A $25,000 surety bond on a DLI form from a Minnesota licensed surety.
- Liability insurance of at least $50,000 per person and $100,000 per occurrence, plus $10,000 property damage.
- Proof of workers’ comp compliance.
- After you’re licensed. Put your company name and license number on both sides of every work vehicle, in letters at least 3 inches high. If your master leaves, the statute gives you 15 business days to notify DLI and 60 days to replace them.
- Need help? Call DLI at 651-284-5034 or email dli.license@state.mn.us.
FAQ
How long does it take to become a plumber in Minnesota?
About four years and 7,000 hours to qualify for the journeyworker exam. Then one more year as a journeyworker before the master exam.
How many CE hours do Minnesota plumbers need?
Journeyworkers and masters need 16 hours every two-year license period, with at least 8 on the plumbing code. Registered unlicensed plumbers need 2 code hours each year.
Do I need a contractor license to work for someone else?
No. Your personal license or registration covers you as an employee. The contractor license is for the business that sells the work.
Is there still a plumbing apprentice license?
You start as a registered unlicensed plumber, or you enroll in a DLI registered apprenticeship. Either way, you work under direct supervision.
Next steps
Start by finding a licensed contractor to work under and registering in iMS. To compare Minnesota with other states, see our plumbing license by state page, the full plumbing license guide, plumbing license cost by state, and plumbing license renewal by state. Working near the border? Check the Wisconsin plumbing license and Iowa plumbing license pages too. When you’re ready to run your own shop, read how to start a plumbing business.
