Montana · Plumbing licensing · official-source guide
Montana licenses plumbers at state level through the Montana Board of Plumbers at the Department of Labor and Industry. The state licenses the person by grade, journeyman and master, not the company. Expect 7,500 hours over five years for journeyman, a 70 percent IAPMO exam on the 2021 Uniform Plumbing Code, and renewal every September 1.
Issued by
Montana Board of Plumbers, Business Standards Division, Montana Department of Labor and IndustryState-level license
Yes
Public lookup
Verify a licenseVerified against agency sources on 2026-09-11. Rules and fees change; confirm with the named authority before relying on this guide.
The Montana Board of Plumbers issues the license. The board sits inside the Business Standards Division of the Montana Department of Labor and Industry, and its licensing page is run at boards.bsd.dli.mt.gov/plumbers. Licensing is statewide. No Montana city runs its own plumber examination, and no city issues a competing plumber license. Section 37-69-301, MCA says that except for the exceptions in 37-69-102, a person working at the field of plumbing in Montana, either as a master plumber or as a journeyman plumber, must first obtain a license under Title 37, chapter 69, part 3. The same section adds a job site rule. A licensed person must carry the license, or proof of licensure, at all times while working on a job site and performing work that requires a license, and the board decides what counts as acceptable proof. The exceptions in 37-69-102 are narrow and specific. An owner of a single family residence used exclusively for the owner's personal use may install the sanitary plumbing and potable water supply piping. Licensure is also not required in a mine, mill, smelter, refinery or railroad, on a farm or ranch not connected to a public water supply and sewage system, for a city or water district repairing its own water and sewer mains, for water conditioner service in a private dwelling, for a private water supply pump, waterline or pressure tank, and for a registered apprentice working under the supervision of a licensed plumber.
Sourcesboards.bsd.dli.mt.gov 1mca.legmt.gov 2mca.legmt.gov 3
Montana licenses the individual by grade. There are two plumber grades, journeyman and master, plus a medical gas endorsement that attaches to a license. Montana does not issue a separate plumbing contractor license to a company. Instead ARM 24.180.507 makes a master plumber declare on the application or the renewal whether that master is the master plumber of record, and name the plumbing business the designation covers. The designation only takes effect once the board receives it. A master may be the master plumber of record for one plumbing business at a time. The master plumber of record supervises all plumbing work the business performs and has to keep that work compliant with licensing laws and building codes. Rule 24.180.507 also fixes when the designation is mandatory. A plumbing business must have a master plumber of record at all times that it advertises plumbing services, bids or contracts for plumbing work, or applies for or renews a plumbing permit. Section 37-69-305(3), MCA closes the loop from the other side. A master plumber may not let the license be used by any other person, firm, corporation or business to pull permits or to do plumbing work. Section 37-69-304(2), MCA adds that a licensed journeyman may work only in the employment of a licensed master plumber unless a board rule says otherwise, and that the master has to observe the journeyman's work at different times and at different levels of work.
Section 37-69-304, MCA sets a record of five years of legally obtained experience in the field of plumbing, met either by working five years in a major phase of the plumbing business, verified by time or pay records, or by completing an apprenticeship program meeting standards set by the department or the United States Department of Labor. ARM 24.180.504 puts numbers on it. A written affirmation from a licensed master plumber or licensed plumbing contractor who employed the applicant has to verify a minimum of 7,500 aggregate hours of experience over a period of not less than five years. An apprenticeship completion certificate from the United States Department of Labor Office of Apprenticeship or a recognized state apprenticeship agency also satisfies the rule, and credit for a registered apprenticeship depends on actually finishing the program. Rule 24.180.504 then lists the substitutions. A first or advanced degree in an approved engineering curriculum, or a baccalaureate degree in an approved engineering technology curriculum, counts as two years of the five. The board may give credit at its own discretion for an unapproved engineering technology curriculum, for parts of such a curriculum, or for a technical institute course, with none of those exceeding two years of the five. Documented practice in steam fitting, hydronics and industrial piping counts toward a maximum of two years. The board's journeyman application, revised 02/09/2023, repeats all three routes.
Section 37-69-305, MCA requires evidence of four years of experience as a licensed journeyman plumber in the field of plumbing, verified by time or pay records of actual plumbing experience. It then requires evidence of three years working with a licensed master plumber or in a supervisory capacity in the field of plumbing, and says plainly that the three years may run concurrently with the four. The statute defines a year for this purpose as 1,500 hours or more of work in a continuous 12 month period. The board's master application, revised 02/09/2023, states the four years as a minimum of 6,000 hours as a licensed journeyman plumber and repeats the 1,500 hour definition of a year. ARM 24.180.506 controls what proof the board takes. It accepts written affirmation from a licensed master plumber or licensed plumbing contractor who employed the applicant, certifying by detailed description that the applicant meets 37-69-305. The same rule shuts a door that is open at journeyman level. Practice in steam fitting, hydronics and industrial piping will not be considered acceptable experience for the master license experience requirement. Applicants coming from a state with no journeyman or master licensing take a different path under ARM 24.180.604. They provide a notarized statement or letter from a qualified individual with direct knowledge of their plumbing experience, equivalent to five years for the journeyman license and nine years for the master license.
Sourcesmca.legmt.gov 1boards.bsd.dli.mt.gov 2rules.mt.gov 3rules.mt.gov 4
The board approves you first, then sends an admission letter that lets you schedule with IAPMO, the International Association of Plumbing and Mechanical Officials. Examinations are built on the 2021 Uniform Plumbing Code as amended by Montana building codes. ARM 24.180.407, amended effective 4/11/26, now says master applicants must pass one written examination at 70 percent or better, and that journeyman applicants must pass two written examinations at 70 percent or better on each, with the first passed before the second may be taken. Two primary sources disagree here, and both are still published. The board's exam information sheet and its journeyman application, revised 02/09/2023, describe a journeyman written examination and a separate hands on practical examination with isometric drawings, and ARM 24.180.607 still conditions a temporary permit on practical examination scores. Treat the amended rule as the operative text and confirm the practical with the board before you plan around it. The exam information sheet gives the question counts as 100 multiple choice for journeyman and 125 for master. The master application describes the master examination as open book with a three hour limit, and says you must bring your own code book, untabbed. Retakes are capped. Failing three written examinations inside the one year an application stays viable forces 20 hours of continuing education before a fourth attempt, and failing the fourth blocks reapplication for one year.
Sourcesboards.bsd.dli.mt.gov 1rules.mt.gov 2boards.bsd.dli.mt.gov 3boards.bsd.dli.mt.gov 4boards.bsd.dli.mt.gov 5rules.mt.gov 6
ARM 24.180.401, amended effective 7/11/26, is the fee schedule. Application fees are $220 for journeyman, $220 for master, $80 for the medical gas endorsement and $220 for out of state. Renewal fees are $160 for journeyman, $200 for master and $24 for the medical gas endorsement. The provisional license fee is $100. The master plumber of record fee is $50. A continuing education provider pays $50 and a continuing education course costs $25. A one time retirement status certificate fee is $25. The rule also says applicants approved to test pay the examination fee directly to the vendor, at a price the vendor sets that varies by examination, and that current vendor examination fees come from the board office. This is a second place where two primary sources conflict. The board's own application forms, both revised 02/09/2023, still print $270 for the journeyman application, $400 for a journeyman by reciprocity, $380 for the master application and $100 for a temporary work permit. The rule is newer than the forms. ARM 24.101.403 adds the department wide charges on top: $5 for a duplicate license, $20 for a license verification, $120 to reinstate an administratively suspended license, $30 for a returned check, and a late penalty equal to 100 percent of the renewal fee.
Sourcesrules.mt.gov 1boards.bsd.dli.mt.gov 2boards.bsd.dli.mt.gov 3rules.mt.gov 4
ARM 24.180.607 gives an applicant for either grade a temporary practice permit once the board approves the applicant to take the examination and the fees arrive. The permit only authorizes journeyman plumber functions. A master applicant holding a temporary practice permit may not perform work that requires a master plumber license, which means a master applicant cannot use the permit to pull permits or run a business as the master plumber of record. The permit terminates on the earliest of three events: 110 days after issuance, the applicant's fourth failure of the written examination, or the applicant failing the practical examination with a score below 65 percent. A second temporary practice permit goes to an applicant who scores between 65 and 69 percent on the practical examination, and the board may also issue a second permit at its discretion to an applicant who could not sit for a scheduled practical examination because of a documented hardship. The board's examination page repeats the 65 to 69 percent rule and says other requests for a second temporary license must be submitted to the board in writing. ARM 24.180.401 prices a provisional license at $100. The board's 2023 application forms describe the same charge as a $100 temporary work permit fee added to the application fee.
Sourcesrules.mt.gov 1boards.bsd.dli.mt.gov 2rules.mt.gov 3boards.bsd.dli.mt.gov 4
ARM 24.101.413 is the department wide renewal date table, and the Plumbers entry is short and consistent. Journeyman Plumber, Master Plumber and Medical Gas Endorsement all renew annually on September 1. There is no two year cycle and no staggered anniversary date for this board, so every Montana plumbing license in the state expires on the same day. Rule 24.101.413 also defines what a timely renewal is. The application has to be complete, carry any required documentation, include the fee, and either bear a United States Postal Service postmark on or before the renewal date or be submitted through the department's online renewal service before 11:59 p.m. Mountain time on the renewal date. Miss it and ARM 24.101.403 applies a late penalty fee equal to 100 percent of the license renewal fee, charged in addition to the renewal fee, for each renewal period the license went unrenewed. ARM 24.180.2102 adds a consequence that catches late renewers specifically. A licensee who does not file a renewal application on time and later files a late renewal must provide documentary proof of completing the required continuing education. ARM 24.101.403 also prices the inactive to active status change as the difference between the inactive and active fees for the remainder of the period.
ARM 24.180.2102 requires each journeyman or master plumber to obtain at least four hours of board approved continuing education annually, and licensees affirm that recurring duty as part of renewal. New licensees are exempt during their first renewal cycle. A licensee moving up from journeyman to master is not exempt and still owes four hours. Credit only counts for courses that received prior approval of the curriculum from the board or the department and that carry a department assigned course approval number, and approval expires when changes in plumbing code, statutes or rules make it stale. Curriculum has to be based on the adopted state plumbing code, Title 37 chapter 69 MCA, Title 50 chapter 60 MCA on building codes and permits, ARM Title 24 chapter 180, ARM 24.301.301 through 24.301.351, or another plumbing subject the board approves. Instructors must be IAPMO certified instructors, approved plumbing instructors from a reciprocity state who also finished the IAPMO train the trainer course for the Uniform Plumbing Code, or licensed plumbers in a Uniform Plumbing Code jurisdiction who meet added conditions. Sponsors give the department at least 15 working days notice of each course. The board may randomly audit up to 50 percent of all renewed active licensees, and licensees keep completion certificates for at least three years. Noncompliance can lead to administrative suspension.
Sourcesrules.mt.gov 1boards.bsd.dli.mt.gov 2boards.bsd.dli.mt.gov 3
There is no published list of reciprocity states for Montana plumbers. ARM 24.180.603, the board's old reciprocity rule, is repealed. What governs now is ARM 24.180.604 on out of state applicants. An out of state applicant for a master or journeyman license may prove prior licensing in another state by submitting a copy of the license or licenses held together with a certified letter of verification from the state or local licensing agency stating the date of licensure and the requirements for licensure. If the qualifications from the state of original licensure are not equivalent to Montana's, the applicant gets credit for the years the original state required and has to document the additional years. Applicants from states with no journeyman or master licensing supply a notarized statement from a qualified individual with direct knowledge of their experience, equivalent to five years for journeyman and nine years for master. Section 37-1-304, MCA sits above that rule. Licensure by endorsement requires an active license in good standing from a jurisdiction whose qualifications, measured at the time of application, are substantially equivalent to Montana's, and where they are not, the board decides whether actual qualifications and work experience cover the gap. The department's published substantial equivalency determinations document does not include plumbers. ARM 24.180.401 prices the out of state application at $220.
Sourcesrules.mt.gov 1mca.legmt.gov 2boards.bsd.dli.mt.gov 3rules.mt.gov 4
ARM 24.180.701 states that any person performing the installation of a medical gas system in Montana shall first obtain an endorsement from the board. The rule then defines installation broadly enough that it catches almost everyone on the job. Installation includes the layout, cutting, joint preparation, fitting, purging and brazing, or any other joint making or assembly process required to install a medical gas system. So a plumber who only brazes the joints still needs the endorsement. Certification means an accreditation from an approved training program acceptable to the board, issuing diplomas, cards or certificates proving the applicant successfully completed training in the installation of medical gas systems under the requirements imposed by NFPA 99C and Section IX of the ASME Welding and Brazing Code. The endorsement itself is the board's approval, signified by an endorsement card or other credential, authorizing a person to install medical gas systems in Montana. The board's medical gas page asks for attached proof of successful completion of a board approved training program and links its own application and checklist. On fees, ARM 24.180.401 charges $80 to apply for the medical gas endorsement and $24 to renew it. ARM 24.101.413 puts that renewal on September 1 annually, the same date as the underlying plumber license.
Sourcesrules.mt.gov 1boards.bsd.dli.mt.gov 2rules.mt.gov 3rules.mt.gov 4
The plumbing license is personal. The business credential sits in a different chapter and a different program. Section 37-45-201, MCA says an individual or business entity may not engage in business as a construction contractor without a current license from the department, and the application must include proof of compliance with workers' compensation laws along with owner, officer, partner or manager details. Section 37-45-102, MCA defines a construction contractor as a person, firm or corporation that in the pursuit of an independent business offers to undertake, undertakes, or submits a bid to construct, alter, repair, add to, subtract from, improve, move, wreck or demolish for another a building or other structure, project, development or improvement attached to real estate. The Construction Contractor License program FAQ published by the Business Standards Division prices the license at $70 for application and renewal, citing ARM 24.227.401 and 37-45-203, MCA, and tells contractors to cover employees under a Montana workers' compensation insurance policy. Section 37-45-104, MCA exempts work on one undertaking or project of a casual, minor or inconsequential nature where the aggregate contract price for labor, materials and everything else is less than $2,500 a job, and blocks splitting a larger job into sub-$2,500 contracts to dodge the chapter. ARM 24.101.413 renews a construction contractor license biennially on its anniversary.
Sourcesmca.legmt.gov 1mca.legmt.gov 2boards.bsd.dli.mt.gov 3mca.legmt.gov 4rules.mt.gov 5
Section 37-69-103, MCA sets the shape of the exposure. The chapter may not be read as penalizing an unlicensed person for hiring or contracting with an unlicensed person to do plumbing work, but a person who engages in the field of plumbing while unlicensed is subject to the penalties in the chapter. The homeowner is not the target. The unlicensed worker is. Section 37-1-109, MCA carries the teeth. The department may issue a cease and desist order on credible evidence that a person is acting, has acted, or is about to act in a Title 37 profession without the required license, with a restricted title or designation without meeting the requirements for that use, or in violation of a statute or rule. A board screening panel, or the department for a program, may assess a penalty of not more than $1,000 a day for each day a cease and desist order is violated. The board may also sue in district court for an injunction, without proving that a legal remedy is inadequate, and recover its costs, investigation costs and attorney fees. A person who knowingly or purposely violates that injunction is guilty of a felony. An officer, agent, partner or member of a business entity who knowingly and personally participates is personally exposed. On the contractor side, 37-45-302, MCA adds a penalty of up to $5,000 and suspension or debarment from public works contracts.
This is the part Montana enforces on the truck and on the website, and it comes with numbers. Section 37-69-301(2), MCA requires a licensee to carry the license, or proof of licensure, at all times while working on a job site doing work that requires a license. Section 37-69-310, MCA sets the civil fines for failing to display it: $100 for a first offense, $250 for a second, and $500 for a third and any subsequent offense, with each day of violation a separate offense. The board may not fine a first offense if the licensee produces proof of licensure to the department within five days of the citation. Section 37-69-319, MCA says who may ask. An employment agency or labor union employee, a building code compliance inspector, a department employee, a person professionally responsible for a job site, or any licensed plumber may demand proof of licensure from someone doing licensed work, and a department employee may issue the citation and collect the fine on the spot. On advertising, ARM 24.180.507(7)(a) requires a plumbing business to have a designated master plumber of record at all times it advertises plumbing services, bids or contracts for plumbing work, or applies for or renews a plumbing permit. ARM 24.180.2301(1)(h) makes allowing false or misleading advertising about the licensee's plumbing business unprofessional conduct, and 37-45-301, MCA makes fraud, misrepresentation or deception in advertising unprofessional conduct for a construction contractor licensee.
Sourcesmca.legmt.gov 1mca.legmt.gov 2mca.legmt.gov 3rules.mt.gov 4rules.mt.gov 5mca.legmt.gov 6
Montana splits code enforcement. The Building Codes Program states that cities, counties and towns may enforce local building, electrical, plumbing and mechanical codes, all or in part, through a program the state certifies, and that everywhere else falls under the Building Codes Program. The state plumbing permit page says the Building Codes Bureau issues plumbing permits outside certified local government areas, and states the rule that matters on commercial work: the service of a Montana licensed master plumber is required on all public and commercial buildings. Homeowners may do their own work on a personal residence that is not for resale or rental. In Missoula, the city Building Division requires a plumbing permit for repairing, replacing, relocating or adding to water and sewer piping, for new fixtures, for water heater replacement, for concealed plumbing behind a fixture swap, and for backflow preventer installation, in both one and two family dwellings and commercial buildings. Commercial plumbing projects in Missoula need plans designed by a licensed professional or master plumber unless approved otherwise, plus an isometric drawing. Mechanical and plumbing are not plan reviewed on one and two family permits in Missoula and get field verified instead. Billings requires online permit submission through its Building Division. Billings also taxes the business separately: any person who conducts business in the city or is based in the city must obtain a business license on or before the date the business commences, valid one year from the month obtained and renewed annually.
Sourcesbsd.dli.mt.gov 1bsd.dli.mt.gov 2ci.missoula.mt.us 3billingsmt.gov 4billingsmt.gov 5
The Montana Department of Labor and Industry runs one public search for every profession and occupation it licenses, including plumbers, medical gas endorsees and construction contractors. The board's own page links it under license verification and lookup, and the same search is linked from the department's Montana Contractor pages for construction contractor registration and for independent contractor exemption certificates. A customer can check the grade, whether the license is active, and the expiration date, which for every Montana plumber is September 1. ARM 24.101.404 is the rule that puts disciplinary orders onto the licensee lookup database, so the search shows more than the existence of a credential. Two checks are worth doing together on a commercial job. Look up the individual master plumber by name, then confirm that master is the master plumber of record for the company writing the estimate, because ARM 24.180.507 requires that designation before the business may advertise, bid or pull a permit, and no change of status is lawful until the board receives written notice of it. If proof cannot be produced on the job site, 37-69-319, MCA lets the person professionally responsible for the site, or a code compliance inspector, demand it and report the failure to the board. A formal written verification carries a $20 fee under ARM 24.101.403.
Sourcesebizws.mt.gov 1boards.bsd.dli.mt.gov 2rules.mt.gov 3mca.legmt.gov 4rules.mt.gov 5rules.mt.gov 6
These are common details other guides publish about Montana, but we could not verify them from the agency source. Confirm them directly before relying on them.
Yes. The Montana Board of Plumbers at the Department of Labor and Industry licenses journeyman and master plumbers statewide under Title 37, chapter 69, MCA. No Montana city issues its own plumber license.
Journeyman plumber and master plumber, plus a medical gas endorsement that attaches to a license. ARM 24.180.507 also lets a master be designated the master plumber of record for one plumbing business.
ARM 24.180.504 requires verification of at least 7,500 aggregate hours of plumbing experience over not less than five years, or a completed registered apprenticeship. An approved engineering degree covers two of the five years.
Section 37-69-305, MCA requires four years as a licensed journeyman plus three years working with a licensed master or in a supervisory capacity, which may run concurrently. A year means 1,500 hours or more in a continuous 12 months.
IAPMO. The board approves you first and issues an admission letter, then you schedule with IAPMO. Examinations use the 2021 Uniform Plumbing Code as amended by Montana building codes, and the pass mark is 70 percent.
Under ARM 24.180.401 the application fee is $220 for journeyman and $220 for master, renewal is $160 for journeyman and $200 for master, the medical gas endorsement is $80 to apply and $24 to renew, and the master plumber of record fee is $50.
September 1, annually. ARM 24.101.413 sets the same date for Journeyman Plumber, Master Plumber and Medical Gas Endorsement. A late renewal adds a penalty equal to 100 percent of the renewal fee.
Four hours a year of board approved, code related continuing education for both grades under ARM 24.180.2102. New licensees are exempt for their first renewal cycle. The board may audit up to 50 percent of renewed active licensees.
The board's reciprocity rule, ARM 24.180.603, is repealed. Out of state applicants go through ARM 24.180.604 and 37-1-304, MCA, with certified verification of prior licensure and credit for the years the original state required.
Not a plumbing contractor license. You need a designated master plumber of record under ARM 24.180.507, and a construction contractor license under 37-45-201, MCA, priced at $70 to apply and renew.
Under 37-1-109, MCA the department can issue a cease and desist order and assess up to $1,000 a day for each day it is violated, and can seek a district court injunction. Knowingly violating that injunction is a felony.
The license or proof of licensure must be carried on the job site under 37-69-301(2), MCA, with display fines of $100, $250 and $500 by offense under 37-69-310. A business must have a master plumber of record before it advertises, bids or pulls a permit.
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