State ladder: apprentice → journeyman → master

Montana plumber license: requirements, reciprocity & renewal

Montana Board of Plumbers, Department of Labor and Industry (Business Standards Division) runs plumbing licensing in Montana. Below: the exact ladder, the transfer doors into Montana from all 50 states, the renewal and lapse lines, and the master-of-record rule for opening a company — every figure from the board's own publications, checked October 22, 2026.

State ladder: apprentice → journeyman → master Checked in part Checked October 22, 2026

How you qualify in Montana

• 5 years (7,500 aggregate hours) of legally obtained plumbing field experience verified by affidavit/voucher from a licensed master plumber or plumbing contractor + pass written AND practical examinations at 70% or better
• Completion certificate from a registered apprenticeship program + pass written and practical examinations
• Engineering-degree route: an approved engineering/engineering-technology degree is accepted as equivalent to 2 of the 5 years of experience (Board checklist, ARM 24.180.504)

Registration, in the board’s terms: Montana does not run a separate state apprentice-registration tier for plumbers on the Board's published requirements; the gate is experience: an experience-verification affidavit of 5 years of legally obtained experience in the field of plumbing, vouched for by an active licensed master plumber or plumbing contractor. The Board checklist (under MCA 37-69-304 / ARM 24.180.504) quantifies the non-apprenticeship route as a minimum of 7,500 aggregate hours over not less than 5 years. Completion of a registered apprenticeship program is the alternative route. Trade-school time can be credited toward the experience requirement as provided in the rule.

Run my Montana numbers in the eligibility checker

Plumbing license reciprocity into Montana

Montana endorses journeyman licenses from: Oregon, Idaho, North Dakota, South Dakota. Journeyman ONLY (Board FAQ, primary): Montana has reciprocity agreements for journeyman licensure with Oregon, Idaho, North Dakota and South Dakota. If you passed BOTH the written and practical journeyman exams in one of those states and your active license has no complaints, you do not retake the Montana journeyman exam; if you never took a practical exam you must take one under ARM 24.180.603. You must still apply for the Montana license — the out-of-state license alone does not authorise work in Montana. Montana does not reciprocate a master license.

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