Your Montana plumbing license is one statewide license, but a journeyman can’t go out on their own with it. Montana law says a licensed journeyman may work only in the employment of a licensed master plumber, and only a master can pull plumbing permits. So if your plan is to get your journeyman card and start taking your own jobs, stop. You need a master license (or a master working for your business) before you run a plumbing company.
Requirements change, so always confirm with the Montana Board of Plumbers before you apply. This guide is general info, not legal advice.
Who licenses plumbers in Montana
Plumbing licenses come from the Montana Board of Plumbers, part of the Department of Labor and Industry’s Business Standards Division. The law is Montana Code Annotated Title 37, Chapter 69, and the board’s rules are in ARM Chapter 24.180.
The license is state level. Permits are a different story. The state Building Codes Bureau issues plumbing permits outside certified local governments, and certified cities, counties and towns can enforce the plumbing code inside their own boundaries. So your license comes from the state, but your permit may come from the city or county where the job is.
A few jobs don’t need a license at all under state law. The big ones: a homeowner doing all the plumbing in a single-family home used only for their own personal use, farms or ranches not hooked to public water and sewer, and private water supply work like the pump, waterline or pressure tank.
License types
The board issues two plumbing licenses plus one endorsement:
- Journeyman Plumber. Lets you do plumbing work while employed by a licensed master plumber.
- Master Plumber. Lets you pull permits and run the plumbing side of a business. A master can’t let anyone else use their license to get permits or do work.
- Medical Gas Piping Installation Endorsement. An add-on for installing pipe used only for medical gases.
There’s no separate apprentice license from the board. State law exempts an apprentice working under the supervision of a licensed plumber. Apprenticeships are registered through Montana’s Registered Apprenticeship program at the Department of Labor and Industry (406-444-4100).
Experience hours
Journeyman. You need 5 years of legally obtained plumbing experience. The board’s application spells that out as at least 7,500 hours over no less than five years, verified by a licensed master plumber or plumbing contractor. You can also qualify by finishing an apprenticeship approved by the U.S. Department of Labor or a recognized state agency. The application allows some credit toward the 5 years for approved schooling, such as an engineering degree or related education (up to 2 years).
Master. You need 4 years (and 6,000 hours) as a licensed journeyman. You also need 3 years either working with a licensed master or in a supervisory role, and those 3 years can overlap with the 4. Montana law defines a year as 1,500 hours or more in a continuous 12-month period. The board’s checklist says steam fitting, hydronics and industrial piping don’t count as master experience.
Coming from a state that doesn’t license plumbers? The master checklist asks for notarized proof of 9 years of equivalent plumbing experience.
Exams
Exams are given by IAPMO, online through its proctored FLEX platform. You must get board approval first. After that, you get an admission letter and schedule with IAPMO.
- Journeyman: two written exams, 70% or better on each. You must pass the first before you can take the second. A rule change effective April 11, 2026 dropped the old “practical” label because both parts were already written.
- Master: one written exam, 70% or better.
The exams are open book. The board’s current materials reference the 2021 Uniform Plumbing Code plus Montana amendments, and IAPMO says your code book has to match the exam year. The board’s site says it expects to update in July 2026 pending new code adoption, so ask which edition applies before you buy a book.
Retake rules: if you fail three written exams within the one-year life of your application, you need 20 hours of continuing education before a fourth try. Fail the fourth and you can’t reapply for a year.
Fees and renewal
The board cut several fees in a rule change effective July 11, 2026. Current fees under ARM 24.180.401:
- Journeyman application: $220
- Master application: $220
- Out-of-state application: $220
- Medical gas endorsement application: $80
- Board-administered exam or reexam: $400
- Provisional license: $100
- Master of record: $50
- Journeyman renewal: $160
- Master renewal: $200
- Medical gas endorsement renewal: $24
Heads up: the application PDFs on the board’s site are dated 2023 and still show the older fees ($270 journeyman, $380 master, $400 out of state). Call the board to confirm what to pay. All fees are non-refundable.
Licenses renew each year. For the current cycle, renewals opened July 2, 2026 and are due September 1, 2026, and the board says the renewal fee is 100% abated if you renew on time. Renew late and fees apply. You renew online through the state’s licensing portal at ebiz.mt.gov/pol.
Continuing education
Both journeymen and masters need 4 hours of code-related continuing education each renewal cycle (ARM 24.180.2102). The course must be approved by the board ahead of time, so check before you sign up.
Bond, insurance and contractor registration
The board’s license pages don’t list a bond or insurance requirement for the plumbing license itself.
Running a business is separate. Montana’s Construction Contractor Registration, handled by the Department of Labor and Industry’s Employment Relations Division, is required if your construction business has employees, is a corporation, or is a manager-managed LLC. The fee is $70, registration lasts two years, and you must show proof of Montana workers’ compensation coverage if you have employees. The application doesn’t list a bond requirement.
Non-plumbers can own a plumbing business, but a master plumber license is required to get plumbing permits. The board has a Master Plumber of Record form for this setup.
Reciprocity
The board’s FAQ and journeyman application say Montana has journeyman reciprocity with Oregon, Idaho, North Dakota and South Dakota. Your license must be active and in good standing. The FAQ says reciprocity does not cover master licenses, and you still have to apply in Montana. You can’t just start working on your out-of-state card.
If you’re coming from Idaho because you heard Idaho reciprocity covers Montana, Washington and Oregon, note that Montana’s own list doesn’t include Washington.
One more wrinkle: in April 2026 the board repealed its standalone reciprocity rule (ARM 24.180.603), calling it duplicative of state law. Out-of-state applicants are now handled under Montana’s general licensure-by-endorsement law, which looks at whether your state’s requirements are substantially equivalent. Military members, spouses and veterans have a separate path under state law. Because of this change, call the board to confirm how your state is treated before you apply.
How to apply
- Pick your license and download the journeyman or master application and checklist from the board’s forms page.
- Gather your proof: the Experience Verification Affidavit or your apprenticeship completion certificate, plus license verification from every state where you’ve been licensed.
- Apply online at ebiz.mt.gov/pol or send a paper application with the fee.
- Wait for board approval and your admission letter, then schedule with IAPMO.
- Pass your exams, get your license, and keep proof of licensure on you at every job site. State law requires it.
Questions: Professional Licensing Customer Service at (406) 444-6880 or DLIBSDHELP@MT.GOV. Scope of practice questions go to (406) 841-2258.
Recent changes
Besides the 2026 fee cuts and the exam and reciprocity rule changes, 2025’s House Bill 276 requires all licensees to keep a current mailing address on file, report changes within 30 days, answer new attestations, and optionally agree to get disciplinary notices by email.
FAQ
Do I need a license to be a plumbing apprentice in Montana?
No board license is required. State law exempts an apprentice working under a licensed plumber’s supervision. Register your apprenticeship through the state’s Registered Apprenticeship program.
Can a journeyman plumber work for themselves in Montana?
No. Montana law says a journeyman may work only in the employment of a licensed master plumber unless board rules allow otherwise. Only masters can pull permits.
How long does it take to become a master plumber in Montana?
At least 5 years to journeyman, then 4 more years as a licensed journeyman. Figure about 9 years total.
Does Montana accept my out-of-state license?
For journeymen, the board lists Oregon, Idaho, North Dakota and South Dakota. Masters don’t get reciprocity. Everyone else applies by endorsement and the board decides if your state’s requirements match. Call first.
Next steps
Comparing states? Start with our plumbing license by state list, or read the full plumbing license guide for how licensing works everywhere. If you’re working near the border, check our Idaho plumbing license page too. And once you’ve got your master card, our guide on how to start a plumbing business walks you through the rest.
