How to become a licensed plumber in Montana

Journeyman level 7,500 hours on the job + state exam What's a journeyman?

Licensing office Montana Board of Plumbers (Department of Labor & Industry) · (406) 444-6880 [2]

The license pathway in Montana

1. 1

   Registered apprentice

   • At least 144 hours a year recommended under state law; UA Local 41 requires at least 450 classroom hours

   You work for a master plumber under an apprenticeship agreement registered with DLI. No plumbing license is required while you work under a licensed plumber as a registered apprentice. [4][8][21][26]

2. 2

   Journeyman plumber

   • 7,500 hours on the job
   • 5 years of experience
   • Yes: two IAPMO exams (100 open-book questions on the UPC, then three virtual diagrams); 70% on each
   • $220 application
   • Yearly by September 1; $160; 4 hours CE

   Installs sanitary plumbing and potable water piping. You need 5 years of legally obtained experience (7,500 hours under the Board's rule) or a completed apprenticeship. A journeyman may work only in the employment of a licensed master plumber unless Board rules allow otherwise. [1][3][5][7][9][10][11][14][16]

3. 3

   Master plumber

   • 4 years of experience
   • Yes: written, 125 questions, 2021 UPC, open book, 3 hours, 70% to pass (IAPMO)
   • $220 application
   • Yearly by September 1; $200; 4 hours CE

   Plans, bids, contracts for and supervises plumbing work. You need 4 years as a licensed journeyman, with 3 years working with a master or as a supervisor. Only masters can pull plumbing permits. [2][11][14][24][27]

Who needs a license in Montana

Montana law says a person working in the field of plumbing, as a master or journeyman, must first get a license, and must carry it on the job site. The field of plumbing means installing, removing, altering or repairing plumbing and drainage systems.

Exceptions include a homeowner plumbing a single-family home for personal use, plumbing in mines, mills and railroads, farms and ranches not connected to public water and sewer, and a registered apprentice working under a licensed plumber. Students doing class or lab work in a college plumbing program are exempt too, but not for work in occupied buildings.

A journeyman may work only in the employment of a licensed master plumber. Only master plumbers can get plumbing permits, which come from the state Building Codes Program or a certified city. [1][2][6][7][8]

Journeyman requirements

The statute asks for "a specific record of 5 years of legally obtained experience in the field of plumbing." You can meet it by working 5 years in a major phase of the plumbing business, verified by time or pay records, or by completing an apprenticeship that meets DLI or U.S. Department of Labor standards.

The Board's rule (ARM 24.180.504) and its checklist say your employers' written affirmation must show at least 7,500 aggregate hours over at least five years, and that credit for a registered apprenticeship depends on completing it. It also lists partial credit of up to 2 years for an engineering degree, approved trade school (Wahpeton in North Dakota, Northern in Havre and Flathead Community College), or steam fitting, hydronics and industrial piping work. [1][9][10]

The exams

Montana's plumbing exams are given by IAPMO after the Board approves you. Exam fees are paid directly to IAPMO.

• Journeyman exam 1: 100 multiple-choice questions on the 2021 Uniform Plumbing Code (UPC) as amended and Montana's plumbing and building code rules; open book; 3 hours.
• Journeyman exam 2: three virtual diagrams; 2.5 hours. The Board's exam sheet calls this the practical exam. Since April 11, 2026 the Board's rule calls both journeyman exams written exams and says you must pass the first before taking the second.
• Master exam: 125 questions; open book; 3 hours.

You need 70% on each. Bring your own UPC book; only factory tabs are allowed. If you fail three written exams within a year, you need 20 hours of CE before a fourth try. The exam sheet names the 2021 UPC, but Montana's Building Codes Program lists the 2024 UPC as effective September 26, 2026, so confirm the exam's code edition with the Board when you apply. [5][11][12][13]

Fees and renewal

Since July 11, 2026, the Board's fee rule sets a $220 application fee for journeyman, master and out-of-state applicants, and yearly renewal fees of $160 for a journeyman and $200 for a master. The Board's checklists (updated February 2023) still show the older $270, $380 and $400 application fees. All fees are non-refundable, and exam fees are paid to IAPMO.

Every plumbing license expires September 1 each year, and renewal opens 60 days before. Licensees need 4 hours of Board-approved CE each year; new licensees are exempt during their first renewal cycle. The Board's renewal page says the FY 2026 renewal fee was 100% abated (waived), though late fees still applied. [3][10][14][15][16][17]

Union and open-shop apprenticeships

Montana Registered Apprenticeship registers plumber and pipefitter apprentices with employers statewide and supplies hour books. MSU-Northern offers online classroom training for plumbing apprentices.

Union programs: UA Local 41 in Butte runs a 5-year program with application periods every January-June and July-December, and UA Local 30 in Billings runs five-year apprenticeship programs. See union vs. non-union and how to get an apprenticeship. [18][19][20][21][22]

If you're licensed in another state

The Board's FAQ says Montana has journeyman-only reciprocity agreements with Oregon, Idaho, North Dakota and South Dakota. If you passed those states' written and practical journeyman exams and have no complaints on an active license, you don't retake the journeyman exam, but you must still apply for a Montana license. Montana does not reciprocate master licenses. The Board repealed its reciprocity rule (ARM 24.180.603) effective April 11, 2026, as duplicative of state law, so confirm the current terms with the Board.

Applicants from other states can submit their license and the original state's requirements; if those fall short of Montana's, you get credit for the years that state required and document the rest. From states with no journeyman or master licensing, you need a notarized statement covering five years (journeyman) or nine years (master) of experience. These applicants take all the exams. See our reciprocity guide. [2][10][23]

Steps to get licensed in Montana

1. Get hired and registered as an apprentice

   Apply to plumbing contractors or a UA program. Your employer registers you with Montana Registered Apprenticeship, and you keep a plumber hour book. [4][18][19]

2. Finish 5 years or the apprenticeship

   Complete the registered apprenticeship and request DLI's completion certificate, or document 5 years of legally obtained experience with an affidavit from the master plumbers or plumbing contractors who employed you. [1][10][25]

3. Apply to the Board of Plumbers

   Apply online through the Board's journeyman page with the $220 application fee. The Board must approve you before you test. [3][12][14]

4. Pass the two IAPMO journeyman exams

   After approval you get an admission letter and schedule with IAPMO. Pass the first exam before you take the second, with 70% on each. Bring your own Uniform Plumbing Code book; confirm the edition with the Board, since its exam sheet names the 2021 UPC and the state adopted the 2024 UPC on September 26, 2026. [5][11][12][13]

5. Renew every year

   Plumbing licenses expire September 1 each year. Complete 4 hours of Board-approved CE each year; new licensees are exempt during their first renewal cycle. [3][16][17]

Where to get the hours

Programs that train plumbers in or for Montana, from their own official pages. Listed by type, not ranked.

• State program

  Montana Registered Apprenticeship

  The state apprenticeship agency at DLI. You apply to plumbing employers, who register you; DLI issues the completion certificate you upload with your journeyman application. [18][19]

• Union

  UA Local 41 / Silver Bow JATC (Butte)

  A 5-year program for plumbing, HVAC, pipefitting and welding with at least 7,500 on-the-job hours and 450 classroom hours, covering much of western and central Montana. Applications are taken online twice a year. [21]

• Union

  UA Local 30 (Billings)

  The plumbers and pipefitters local in Billings, which runs five-year apprenticeship programs. Contact the local for how to apply. [22]

• School

  MSU-Northern Apprenticeship Education

  Online related-training courses for apprentices working for an approved plumbing or electrical firm in Montana, recognized by DLI's apprenticeship program. [20]

Licensed in another state?

Questions people ask