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

Montana has no master HVAC, master mechanical, refrigeration or HVAC contractor license; MCA Title 37 chapter 70 (Heating, Ventilation, Air Conditioning) is repealed and the Department of Labor & Industry runs no HVAC program. The nearest state credential is the construction contractor license that every contractor with employees must hold from January 1, 2026 under MCA Title 37 chapter 45 (formerly the $70 construction contractor registration under MCA 39-9): it is issued to the business on proof of workers' compensation compliance with no examination, experience or trade qualification, and a sole operator with no employees instead obtains a $125 Independent Contractor Exemption Certificate, for which 'a test is not required'. Licensed electricians and plumbers are exempt from that chapter, which is why Montana's larger cities license those two trades by their state cards but treat HVAC firms as ordinary contractors: Missoula issues a contractor business license (expires February 28) on $300,000 liability insurance, background checks and state registration, with a $3,000 bond only for gas fitting; Great Falls issues a 'Mechanical' contractor license type for $45 a year on proof of state registration or ICEC, $1,000,000 liability insurance and, for gas fitting, a city-licensed gas fitter of record; Billings and Bozeman require only a city business license ($75 in Bozeman). Boiler operation is separately licensed by the state under MCA 50-74 (six engineer classes, exam-based, no reciprocity provision), and mechanical permits under the state-adopted International Mechanical and Fuel Gas Codes are open to any permit applicant. A master HVAC or HVAC contractor license from another state therefore transfers to nothing in Montana; the holder who wants to run an HVAC business applies for the state construction contractor license (or ICEC), a city business/contractor license where required, and keeps federal EPA Section 608 certification for refrigerant work.