Plumbing License Montana: Journeyman, Master and the Exam Sheet That Contradicts the Application (2026)

Montana licenses plumbers at two levels, journeyman and master, through the Montana Board of Plumbers under the Department of Labor & Industry. That much every guide gets right. What almost none of them tell you is that the Board is currently publishing two different descriptions of the same journeyman exam, and the one still sitting on the older application form will send you into the testing center prepared for the wrong exam, studying the wrong code book, and without the book you are actually required to bring.

This guide walks the real Montana plumbing licensing process as the Board and the statute define it in 2026: the two licenses, the hours, the exams as currently administered, the verified fees, the temporary practice permit and its 110-day clock, and the one statutory sentence that governs who you are legally allowed to work for.

This is a walkthrough of the licensing process. It is not exam preparation and not a study guide.

The Two Montana Plumbing Licenses

Montana Code Annotated § 37-69-301(1) states it plainly: except for the listed exceptions, a person working at the field of plumbing in Montana, "either as a master plumber or as a journeyman plumber, shall first obtain a license."

There are two licenses. There is no separate "plumbing contractor license" issued by a contractor board, and there is no apprentice license (apprentices register with the Department rather than being licensed). Montana also issues a medical gas endorsement as an add-on credential, not a standalone license.

§ 37-69-301(2) adds a requirement most states do not put in statute: a licensee "shall carry the license, or proof of licensure, at all times while working on a job site and performing work that requires a license." Acceptable proof is determined by the Board. Leaving the card in the truck is not a technicality in Montana; it is a statutory duty.

Journeyman Plumber: Requirements

Under § 37-69-304(1), a journeyman applicant needs a specific record of 5 years of legally obtained experience in the field of plumbing, satisfied either by:

• 5 years in a major phase of the plumbing business, verified by time or pay records; or
• completion of an apprenticeship program meeting the standards set by the Department or the U.S. Department of Labor, Bureau of Apprenticeship.

Credit toward the experience requirement may be given for time spent at an accredited trade or other school specializing in plumbing training, if the Board approves it.

The Board's own journeyman application states the experience requirement as 5 years and 7,500 aggregate hours. Experience is documented on the Board's Experience Verification Affidavit, and each employer you want counted must complete a separate form. The affidavit carries an explicit instruction: the applicant cannot verify their own hours.

The one sentence that decides who you can work for

§ 37-69-304(2) is the most consequential sentence in Montana's plumbing chapter, and it is printed directly on the Board's application form:

"A licensed journeyman plumber may perform work only in the employment of a licensed master plumber unless otherwise permitted by rule of the board. Performing work in the employment of a licensed master plumber means the licensed master plumber shall observe the journeyman plumber's work at different times over the course of employment and for different levels of plumbing work."

Read the second half carefully, because that is where Montana goes further than most states. The statute does not merely require that a master plumber exist somewhere on the org chart. It defines "in the employment of" as actual observation — repeated, across different times and across different levels of work. A master plumber whose only connection to a company is a name on a form is not, by the statute's own definition, employing anyone.

That definition is the reason Montana's qualifier arrangements have to be genuine. We come back to it below.

Master Plumber: Requirements

Under § 37-69-305(1), a master applicant must show:

• 4 years of experience as a licensed journeyman plumber in the field of plumbing, verified by time or pay records of actual plumbing experience; and
• 3 years of experience — which may run concurrently with the 4 years — either working with a licensed master plumber or in a supervisory capacity in the field of plumbing; and
• satisfactory completion of the Board's master examination.

Two details in that provision are worth more than they look.

First, § 37-69-305(2) defines a year. "For purposes of subsection (1), 1 year of experience is 1,500 hours or more of work in a continuous 12-month period." Montana does not leave "a year" to interpretation. The Board's master application translates the requirement as 4 years and a minimum of 6,000 hours at journeyman level or higher, which is exactly 4 × 1,500. If you worked 900 hours in a calendar year, that year does not count, no matter what the calendar says.

Second, the three years run concurrently. The requirement is 4 years as a licensed journeyman, 3 of which were spent working with a master or in a supervisory capacity. It is not 7 years. A number of competing pages present it as sequential, which adds three years to a plumber's timeline that Montana never asked for.

The experience that does not count

The Board's master checklist contains a restriction that appears nowhere in the aggregator coverage:

"Practice in the fields of steam fitting, hydronics, and industrial piping will not be considered as acceptable experience in the field of plumbing for the master license experience requirement."

If a meaningful share of your journeyman-level hours came from hydronic heating or industrial process piping, plan for the possibility that those hours will not carry you to master, and document your sanitary and potable-water work separately from the start.

The Exams: What the Board Actually Administers Now

Montana's plumbing examinations are administered by IAPMO (the International Association of Plumbing and Mechanical Officials), not by PSI, Prov, or Pearson VUE. Candidates schedule through IAPMO after the Board approves the application, and examination fees are paid directly to IAPMO. Confirm the current exam fee with IAPMO before budgeting; the Board does not set it.

Per the Board's current Plumbing Licensing Information sheet:

Journeyman examination

• 100 multiple-choice questions
• Based on the 2021 Uniform Plumbing Code as amended, plus the Statutes and Rules Relating to the Board of Plumbers and Building Codes
• Open book, with a three-hour time limit
• A practical examination consisting of three virtual diagrams, limited to two and a half hours
• 70% required to pass the written and 70% to pass the practical, graded separately

Master examination

• 125 multiple-choice questions
• Based on the 2021 Uniform Plumbing Code as amended, plus the Statutes and Rules
• Open book, three-hour time limit
• 70% to pass
• No practical examination

Candidates must bring their own 2021 UPC code book. Code books will not be provided at the examination, and they are inspected before and after the exam to confirm no examination information was written in them. A packet of the Board's statutes, rules, and code amendments is provided to you at the exam and can also be downloaded from IAPMO's Montana testing page.

The contradiction on the Board's own website

Here is the accuracy problem that costs Montana candidates real money.

The Board's older journeyman application PDF is still live and still says the journeyman exam is based on the 2012 Uniform Plumbing Code, is closed book, runs two and a half hours for the written portion, and includes a four-hour practical made up of isometric drawings and a pressure loop.

The Board's current exam information sheet (revised January 2023) says the journeyman exam is based on the 2021 UPC, is open book, runs three hours, and has a two-and-a-half-hour practical made up of three virtual diagrams.

Every one of those five facts changed. A candidate who prepares from the application PDF studies a code cycle nine years out of date, prepares for a closed-book exam that is now open book, budgets the wrong amount of time for both portions, expects a hands-on pressure loop that has been replaced by virtual diagrams, and — worst of all — arrives without the code book the current exam requires them to bring and that will not be supplied on site.

Multiple competing guides reproduce the stale figures verbatim, because they read the application and stopped there. Use the exam information sheet, and confirm with IAPMO when you schedule. Where a Board's own documents disagree, the more recently revised one and the testing vendor are the safer authorities.

What happens when you fail

ARM 24.180.407(3) sets a consequence structure competitors do not mention. If an applicant fails three written examinations within the one-year period of an application's viability, the applicant must submit proof of completing 20 hours of continuing education before being approved to sit a fourth time. An applicant who fails the fourth written examination may not reapply for licensure for one year.

That is a hard stop, not a fee. Plan the first attempt accordingly.

The Temporary Practice Permit and Its 110-Day Clock

Montana lets you work while your application is pending, on tightly defined terms set by ARM 24.180.607 and summarized on the Board's application checklists:

• An applicant for either the journeyman or the master license may be issued a temporary practice permit, but the permit authorizes only journeyman functions. Master applicants holding a temporary permit may not perform work requiring a master license.
• The permit is issued upon Board approval to take the exam and receipt of the appropriate fee.
• The permit terminates 110 days after issuance, or upon the applicant's fourth failure of the written examination, or upon failure of the practical examination with a score below 65 percent — whichever comes first.
• A second temporary permit will be issued to an applicant who scores between 65 and 69 percent on the practical, or, at the Board's discretion, to an applicant who could not sit a scheduled practical because of a documented hardship.

The journeyman application also requires you to name the Montana master plumber you will be employed by and that master's license number in order to receive the temporary permit — § 37-69-304(2) applied at the permit stage.

Verified Fees

These are the amounts published on the Board's current application checklists. All Board fees are non-refundable. Fees are set by the Board and the Legislature and change; verify current amounts with the Montana Board of Plumbers before you send payment, and confirm exam fees directly with IAPMO.

• Journeyman — application fee: $100
• Journeyman — license fee: $170 (the Board recommends paying both together, $270 total, to expedite processing)
• Master — application fee: $380
• Temporary journeyman work permit: $100 (in addition to the application fee)
• Master Plumber of Record designation form: $50
• Examination fees: paid directly to IAPMO — confirm with the vendor

Processing: a complete, routine application is processed within 30 days. Applications deemed non-routine must be complete 15 days before a Board meeting and may require you to appear before the Board.

Renewal and Continuing Education

Montana plumbing licenses expire annually on September 1. Renewal requires 4 hours of Board-approved continuing education completed prior to the next renewal cycle.

Two wrinkles from ARM 24.180.2102 that the Board calls out explicitly on its own forms:

• New licensees are exempt from the CE requirement during their first renewal cycle.
• Licensees moving from journeyman to master are not exempt — a plumber who upgrades still owes at least four hours.

The Board mails a renewal notice roughly 45 days before expiration to the preferred address on file, and states that failure to keep your address current may result in late fees. Keeping the address updated is on you.

Who Does Not Need a License

§ 37-69-102(1) lists the permanent exceptions. Licensure is not required when:

• an owner of a single-family residence used exclusively for the owner's personal use installs all sanitary plumbing and potable water supply piping, or a mobile home or manufactured housing dealer connects a home to existing sanitary and potable water facilities as part of delivery and setup;
• the work is in any mine, mill, smelter, refinery, or railroad;
• the work is on a farm or ranch not connected to public water supply and sewage disposal systems;
• cities, towns, water districts, and water user associations extend, repair, or replace their own water and sewer mains;
• the work is installation of water conditioner services in private dwellings;
• it is minor work by employees or agents of an appliance dealer incidental to installing an appliance purchased from the dealer;
• a qualified person appointed by the water system's administrative authority installs a water meter;
• in the case of a private water supply, the work is installing the pump, waterline, or pressure tank — inside or outside the structure;
• the person is a registered apprentice working under the supervision of a licensed plumber; or
• the person is a student enrolled in an accredited plumbing training program doing classroom or lab assignments. That exception explicitly does not authorize work that will be incorporated into an occupied structure or connected to a system requiring a licensed plumber.

§ 37-69-102(3) adds a rarely used safety valve: if a licensed person is not available, a county, city, or town council or commission — or a water or sewer district board — may by ordinance, rule, or resolution authorize an unlicensed person to perform plumbing work on a temporary basis, but only after giving the Board reasonable notice by certified letter and either receiving Board approval or getting no response within 30 days of the postmark. The authorization must be withdrawn once a licensed person is reasonably available.

The Business Layer: Master Plumber of Record

Holding a master license is not the same thing as being the licensed person a plumbing company operates behind. Montana handles that with a separate designation called the Master Plumber of Record, governed by ARM 24.180.507 and administered on a dedicated Board form.

The Board's Master Plumber of Record form opens by reciting the authority the designation carries:

"A master plumber is the only person authorized by Montana law to plan, estimate, bid, contract for and supervise plumbing work in the state of Montana, and may do the work of a journeyman plumber."

Under ARM 24.180.507, the master plumber of record is responsible for supervising all plumbing work performed by the plumbing business for which they are designated. A master plumber may be the master plumber of record for only one plumbing business at any one point in time. Designation and termination must be reported to the Board in writing, and no change of status is lawful until the Board receives actual written notice.

If you are an owner without a Montana master license — or a company expanding into Montana — that designation is the thing standing between you and legally bidding work. We break the whole mechanism down in Montana's Master Plumber of Record rule, including the Board's position paper on when a business must name more than one.

Where a Qualifying Agent Fits in Montana

If you own a plumbing business in Montana and you are not personally a licensed Montana master plumber, you have two honest routes: earn the credential yourself, or employ a licensed Montana master plumber who takes the master plumber of record designation for your company.

That second route is what a qualifying agent is. And Montana's statutes make the shape of a compliant arrangement unusually clear, because the state defined the relationship in terms of conduct rather than paperwork:

• § 37-69-304(2) defines employing a journeyman as the master observing that journeyman's work repeatedly and across different levels of work.
• § 37-69-323 provides that a master plumber "may employ only apprentice plumbers registered with the state department of labor and industry and only journeyman plumbers who are licensed by the state of Montana," and makes the master responsible for ensuring that all work performed by those employees complies with the state plumbing code. The same section exposes the master to charges of unprofessional conduct under § 37-1-316 and liability for false swearing under § 45-7-202 for providing the Department false information about an employee's experience or skill.
• § 37-69-305(3) prohibits a master from allowing the license "to be used by any person or firm, corporation, or business other than the master plumber's own" for obtaining permits or doing plumbing work. The Board's own position paper resolves what "own" means: the business with which the master plumber is associated as the master plumber of record.

Put together, Montana is describing someone genuinely inside the company: supervising the work, observing it in person, accountable for code compliance, and personally exposed if the paperwork is false. That is an employee, and The Licensing Company places qualifiers as W-2, full-time employees of the business they qualify — never on a percentage, a flat fee, a per-project arrangement, or a 1099. Montana's plumbing chapter does not contemplate any of those, and § 37-69-305(3) names the alternative for what it is. If you have heard "renting a license" described as a shortcut, read why that is a trap.

If you already hold a Montana master plumber license and want to put it to work properly, you can become a qualifying agent.

How Much Does a Montana Plumbing License Cost?

The government side is knowable and is listed above: the Board's application and license fees, the IAPMO exam fees, the $50 master plumber of record designation, annual renewal, four hours of continuing education, and whatever bonding and liability insurance your work and your local jurisdiction require. All of those are set by the Board, the vendor, or your insurer, and all change — verify before you budget.

The question business owners actually ask is different: what does it cost to solve the problem of not having a Montana master plumber to carry the master plumber of record designation, so the company can legally bid and contract? That one has no honest flat number. It depends on whether you already employ a Montana master, how quickly you need to be operating, how many states you are expanding into, the volume and risk profile of the work, and how long the arrangement needs to last. Anyone quoting a single figure before they understand your situation is guessing. If that is where you are, start with the consultation options or hire a qualifying agent.

Montana Plumbing License FAQ

Does Montana have a state plumbing license? Yes. The Montana Board of Plumbers licenses journeyman and master plumbers statewide under Title 37, chapter 69. Apprentices register with the Department rather than holding a license, and there is a separate medical gas endorsement.

How many hours do I need for a Montana journeyman plumber license? Five years of legally obtained plumbing experience, which the Board's application states as 5 years and 7,500 aggregate hours — or completion of an approved apprenticeship program. Hours are documented on the Board's Experience Verification Affidavit, and you cannot verify your own.

How long does it take to become a master plumber in Montana? Four years as a licensed journeyman, with three of those years — running concurrently, not consecutively — spent working with a licensed master or in a supervisory capacity. Under § 37-69-305(2) a year means 1,500 or more hours in a continuous 12-month period, so the Board's checklist states the requirement as 6,000 hours minimum.

Is the Montana journeyman plumber exam open book or closed book? The Board's current exam information sheet says open book, three hours, 100 questions on the 2021 Uniform Plumbing Code, with a separate two-and-a-half-hour practical of three virtual diagrams. An older application PDF still on the Board's site says closed book on the 2012 code with a four-hour hands-on practical. Follow the current exam sheet and confirm with IAPMO when you schedule — and bring your own code book, because none is provided.

Can a journeyman plumber work independently in Montana? No. Section 37-69-304(2) provides that a licensed journeyman may perform work only in the employment of a licensed master plumber, and defines that employment as the master actually observing the journeyman's work at different times and across different levels of plumbing work.

Who can bid and contract for plumbing work in Montana? The Board's Master Plumber of Record form states that a master plumber is the only person authorized by Montana law to plan, estimate, bid, contract for, and supervise plumbing work in the state. A plumbing business operates behind a designated master plumber of record.

How often does a Montana plumbing license renew? Annually, expiring September 1, with four hours of Board-approved continuing education. New licensees are exempt during their first renewal cycle; plumbers upgrading from journeyman to master are not.

This guide explains Montana's plumbing licensing process and is not exam-preparation material. Fees, hours, code cycles, exam formats, and rules are set by the Montana Board of Plumbers, the Montana Legislature, and IAPMO, and change over time — always verify current requirements with the Board and the testing vendor before applying. Related reading: HVAC license Montana, electrician license Montana, and the national explainer on journeyman vs. master plumber. For help placing a licensed Montana master plumber as a compliant, W-2 qualifying agent, explore your options or browse guides for other states.