Plumbing and HVAC rules in Montana

Plumbers in Montana hold master or journeyman licenses from the Board of Plumbers, and there's no separate license for a plumbing business.^{1, 2, 3}

Montana's Department of Labor and Industry has a Board of Plumbers and a State Electrical Board but no board for heating and cooling work. Ask your city or county whether it licenses heating and cooling contractors.³

Your local building department can tell you which plumbing and mechanical codes apply where you live.

Where Montana runs the program, anyone in the business of installing, altering or repairing plumbing needs a state plumbing permit, though homeowners working on their own home are exempt and certified cities and counties run their own programs. State law exempts homes of fewer than five units from state mechanical permits, so only a local program would require one.^{4, 5}

If your home has a backflow preventer, your water utility can tell you whether it needs testing and who can test it.