Moving to Montana as a journeyman HVAC technician: every state's rule

Montana does not license HVAC technicians at any level, and none of its larger cities does either. The former HVAC licensing chapter, MCA Title 37 chapter 70, is repealed, and the Department of Labor & Industry's list of 41 licensing programs contains electricians, plumbers, boiler operators, elevator mechanics and construction contractors but nothing for heating, cooling, refrigeration, sheet metal or gas fitting. HVAC installers work for a construction contractor that, since January 1, 2026, must hold a Montana construction contractor license under MCA Title 37 chapter 45 (proof of workers' compensation, no trade exam; a sole operator without employees uses the $125 Independent Contractor Exemption Certificate instead), and the work is inspected under the state-adopted International Mechanical and Fuel Gas Codes through state or certified-city mechanical permits that carry no licensing condition. The only adjacent state credential is the boiler engineer license under MCA 50-74-301 to 50-74-304, which anyone operating a covered steam or hot-water boiler must hold (six classes from limited low-pressure to first class, by experience and department exam, with no reciprocity provision). Billings, Missoula, Great Falls and Bozeman require a city business or contractor license from the HVAC business (Missoula: $300,000 liability insurance and employee background checks; Great Falls: a 'Mechanical' contractor license type at $45 per year with $1,000,000 insurance and a city-licensed gas fitter of record for gas fitting; Bozeman: $75), but none tests or licenses individual HVAC journeymen. An out-of-state journeyman HVAC license therefore has nothing to transfer to in Montana; the only credential every technician must carry is federal EPA Section 608 certification for handling refrigerants.