Montana Plumbing Workers Comp Rates (2026)
Montana does not publish its plumbing class figures online. Across the 26 states that do, the median typical premium is about $2.25 per $100 of payroll. Ask a carrier or the state's rating bureau for the current Montana figure.
No official Montana figure is available online, so the numbers below use the US median of the states that publish one.
Montana class code for plumbing
- 5183: Plumbing NOC & Drivers
- 5188 (Sprinkler Installation & Drivers)
Plumbing work involves back strain, cuts, burns from soldering and hot water, and work in crawl spaces and other confined spaces.
What comp costs per plumber in Montana
The Bureau of Labor Statistics counts 1,860 plumbers, pipefitters, and steamfitters on payrolls in Montana (May 2025), the 42nd largest workforce among the 50 states and DC. The median wage is $38.44 an hour, 25% above the US median of $30.67.
Plumbers, pipefitters, and steamfitters make up about the same share of Montana jobs as they do nationally (location quotient 1.22).
At the US median of $2.25 per $100 of payroll (Montana does not publish its figure online), comp on one worker at that wage costs about $0.86 for every hour worked, or $1,799 a year full time. A 2-person crew comes to roughly $3,598 a year in premium before any experience mod.
Because premium is charged on payroll, who you hire moves the bill. Montana pay runs from $23.20 an hour at the 10th percentile to $48.49 at the 90th, so the same rate costs $0.52 an hour on a new hire and $1.09 on a senior hand.
Workers comp requirements in Montana
- Coverage required: 1 employee; out-of-state policies are not accepted for construction work
- Owners and sole proprietors: Excluded by default; construction independent contractors need an Exemption Certificate (ICEC)
- State fund: Competitive state fund (Montana State Fund)
- Waiting period: 4 days (or 32 work hours); retroactive if disability lasts more than 21 days
- Penalty for going without: Double the premium owed (minimum $200), up to $1,000 plus $100 per day, escalating to $50,000
Montana does not accept out-of-state workers comp policies for construction work performed in the state.
Montana vs neighboring states
- Idaho: about $2.39 per $100 of payroll
- North Dakota: about $2.00 per $100 of payroll
- Wyoming: about $2.39 per $100 of payroll
Montana does not publish its figure, so the first row is the US median. Among neighbors that publish, North Dakota is the cheapest for plumbing comp at about $2.00 and Idaho the most expensive at about $2.39 per $100 of payroll.
Working across the line into North Dakota or Wyoming needs separate coverage from that state's fund. A private policy's other-states coverage (item 3.C) does not reach monopolistic states.
What moves a plumbing comp bill
- Plumbing rates sit in the middle of the construction classes; the swing comes from your experience mod. Trench and excavation injuries are the costly claims, so trench-safety training pays back quickly.
- Some states split residential and commercial plumbing into different classes. If you do both, make sure the payroll for each is recorded so the cheaper work is not rated at the higher class.
- Apprentices carry the same class rate as journeymen, but their lower wages mean less premium per hour. Your payroll mix matters as much as the rate.
- Uninsured subs (excavators, drywall patchers) get added to your payroll at audit unless you collect certificates before they start.