Plumbing Contractor License in Montana: Requirements, Qualifier, Bond and Exams

Yes — statewide, but not through a contractor license.

The Montana Board of Plumbers, part of the Department of Labor & Industry, licenses plumbers in two classes, Journeyman and Master, and there is no separate plumbing contractor license class.

Contracting authority is the master plumber license: only a licensed master plumber may plan, estimate, bid, contract for and supervise plumbing work, and only Master plumbers may apply for and obtain plumbing permits.

The requirement has recorded edges: it applies to a person working in the field of plumbing as a master or journeyman, subject to statutory exceptions such as owner-occupied single-family homes, and a 1998 Montana Attorney General opinion, annotated in the board's code compilation, reads it to reach work in an incorporated city or town, in an area served by a public water supply or sewer, or work that connects to one — so confirm coverage with the board before assuming work outside town limits is outside it.

The business layer sits on top: contractors hiring employees must apply for the state Construction Contractor License, and a sole proprietor without employees should confirm with DLI whether it reaches them (see the agency section).

Two Department of Labor & Industry bodies are in play.

The Board of Plumbers issues the plumbing licenses — Journeyman and Master — and the master license is the one that carries contracting authority, because there is no separate plumbing contractor class.

The Construction Contractor License (CCL) program issues the business license: since January 1, 2026, the CCL has been required under MCA Title 37, chapter 45, replacing the former construction contractor registration.

Who must hold it: contractors hiring employees must apply, and DLI's CCL FAQ says the licence specifically targets contractors with employees, as well as corporations and manager-managed LLCs, regardless of employee count; our research leaves open whether a sole proprietor without employees needs it, so ask DLI.

For a firm or corporation, the statute is explicit that the examination and licensure of one individual or principal of the firm satisfies the firm's master plumber requirement — but not the journeyman requirements for its workers.

The classes you will encounter are therefore the two plumbing licenses plus the entity-level CCL, with no separate plumbing contractor class anywhere in the structure.

Montana's qualifier is a master plumber: the person whose license lets the business bid, contract, supervise and pull permits.

A journeyman license does not authorize running or advertising a plumbing business, and a licensed journeyman may work only in the employment of a licensed master plumber unless a board rule permits otherwise.

To hold the master license, an applicant needs 4 years as a licensed journeyman, with 3 of those years — which may run concurrently — working with a licensed master plumber or in a supervisory capacity, and one year means 1,500 hours or more of work in a continuous 12-month period.

The journeyman rung underneath takes 5 years (7,500 hours) of legally obtained plumbing experience or a registered apprenticeship completion certificate.

The business designates its master by filing the Master Plumber of Record form with a $50 fee, the CCL itself lists no qualifier requirement, and the Board of Plumbers says a large or multi-location plumbing business may need to name more than one master plumber of record so all work is adequately supervised.

The trade exam sits on the individual, and it is scheduled through IAPMO after the Board of Plumbers approves the application; exam fees are paid directly to IAPMO.

The master plumber exam is 125 multiple-choice questions on the 2021 Uniform Plumbing Code as amended plus board statutes and rules, open book with a 3-hour limit, and candidates bring their own tabbed code book; a minimum score of 70% is required to pass.

The crew's journeyman rung is examined separately: 100 multiple-choice questions on the same code and statutes, open book with a 3-hour limit, plus a practical exam of three virtual diagrams limited to 2.5 hours, also at 70% to pass.

On the business side, the CCL application checklist lists no trade exam, and our research names no separate business-and-law exam for Montana plumbing businesses — confirm the exam lineup with the board before you schedule study time.

The requirements on record are thin.

The CCL application checklist lists no bond requirement, and our research found no bond or insurance minimum attached to the master-plumber-of-record arrangement either — treat that as a gap in our research rather than a confirmed absence, and ask the Board of Plumbers what applies before you bid.

The one insurance requirement the research confirms is workers' compensation: contractors hiring employees in Montana must cover them under a Montana workers' compensation policy.

HVACHires' separate guide to contractor license bonds and insurance explains what a licence bond is and gathers state-by-state bond amounts and general-liability minimums.

The CCL costs $70 to apply and $70 to renew, renews on the anniversary of issuance, and carries no continuing-education requirement.

Naming your master costs $50 — the Master Plumber of Record form fee.

The master license itself is $380 to apply, plus $100 for a temporary journeyman work permit if requested, and Montana plumbing licenses expire annually on September 1; our sources did not capture the renewal fee amount for the plumbing licenses, so ask the board before you budget the renewal.

Master and journeyman licensees must complete 4 hours of board-approved continuing education each license year, with new licensees exempt for their first renewal.

Only at the journeyman level, and only with four states.

Reciprocal licensees must still apply for a Montana license before working.

For a plumbing business this lands on the qualifier seat: an out-of-state master cannot step into the master-plumber-of-record role on a home-state license, because Montana does not reciprocate a master license — the owner or hire qualifies through Montana's own experience and exam requirements.

Our research found no reciprocity arrangement specific to the CCL; it is a business license you apply for, so confirm current treatment with DLI.

The board's process starts with the master: one who stops being a master plumber of record files a Letter of Disassociation with the board.

Our research did not find a deadline for the business to name a replacement, so ask the board what window applies and treat the seat as vacant until a new master is filed.

Two guardrails shape the search.

A master plumber may not allow their license to be used by any person or business other than their own to obtain permits or do plumbing work, so you cannot borrow a retired master's license to keep permits flowing.

And because one licensed individual or principal satisfies the firm's master plumber requirement, that coverage leaves when the principal does — a large or multi-location operation that already carries more than one master plumber of record has a built-in fallback.

Since a replacement must already hold the master license, line up the next master before the current one walks; HVACHires' separate qualifying agent guide covers what a qualifier is, whether one licence holder can qualify several companies, and what the arrangement pays.

Separately, CCL licensees must report ownership, name or officer changes to the department within 30 days.

The business license itself changed: since January 1, 2026, Montana requires a Construction Contractor License under MCA Title 37, chapter 45, the licence aimed at contractors with employees and at corporations and manager-managed LLCs.

The 'replaces the former construction contractor registration' reading comes from DLI's program pages rather than the statute line, so work from DLI's current Construction Contractor License pages before you rely on an older form.

The Board of Plumbers' side — the master plumber license and the master-plumber-of-record form — is separate from that change.