Montana Plumbing Statutes, Administrative Rules, and Licensing
Licensing framework
Montana regulates plumbing under the Montana Code Annotated, Title 37, Chapter 69, and board rules in the Administrative Rules of Montana, Title 24, Chapter 138. The Board of Plumbers, within the Department of Labor and Industry, issues licenses and enforces practice standards. The license categories include master plumber, journeyman plumber, apprentice plumber, and plumbing contractor. A journeyman works under a master’s supervision; a master may supervise plumbing work and qualify a plumbing contractor; an apprentice must work under required supervision while accumulating experience. Verify current hour and exam requirements in the board’s rules, because the board updates them.
Compliance points tested
- License required: A person may not perform plumbing work requiring a license without holding the appropriate license or working under an exempt/supervised arrangement.
- Permits and inspections: State licensing does not replace local permits. Work must be permitted and inspected under the adopted plumbing code and local ordinance.
- Discipline: The board can act on unlicensed practice, code violations, incompetence, false statements on applications, and failure to obtain required continuing education.
- Reciprocity: Out-of-state license holders must apply through the board’s reciprocity process; a license from another state is not automatically valid in Montana.
- Continuing education: License renewal requires the board-required continuing education; keep certificates.
Worked example
A homeowner hires a handyman to replace a water heater. The handyman holds no plumbing license and says the work is “minor.” In Montana, water heater replacement is plumbing work; a license and any required local permit are triggers. The installer must be licensed or supervised as the board rules allow, and the installation must meet the UPC and manufacturer instructions. The inspector can reject the work, and the board can pursue unlicensed practice. The reasoning: licensing attaches to the scope of plumbing work, not to the size of the invoice.
Traps that cost marks
- Assuming a local business license is a plumbing license.
- Letting an apprentice work unsupervised.
- Treating an out-of-state license as automatic reciprocity.
- Skipping continuing education because the license has not expired yet.
- Believing a permit is unnecessary because the state license is current.