Michigan Plumbing Workers Comp Rates (2026)
The published Michigan pure premium for plumbing workers comp, class 5183 (Plumbing (with related phraseology: pump installation domestic, lawn sprinkler systems underground, water softener installation, sewer cleaning building connections, pipe or boiler insulation)), is $1.105 per $100 of payroll (effective January 1, 2026). Carriers multiply it by their own filed multiplier, so a typical premium is about $1.66.
A pure premium covers expected claims only. Each carrier files its own multiplier for expenses; in the states that publish the full list, the median is about 1.5, which is what the typical premium here uses. Your quote can be lower or higher. Source.
Michigan class code for plumbing
- 5183: Plumbing (with related phraseology: pump installation domestic, lawn sprinkler systems underground, water softener installation, sewer cleaning building connections, pipe or boiler insulation)
Michigan is an independent bureau state that uses NCCI-style four-digit codes (the manual contains NCCI copyrighted material) but has Michigan-specific classes for several trades, e.g. 5476 painting instead of 5474, 5550 HVAC instead of 5537, a 5551 pitched vs 5552 flat roofing split, and 9521 for carpet and resilient flooring instead of 5478.
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 Michigan
The Bureau of Labor Statistics counts 14,120 plumbers, pipefitters, and steamfitters on payrolls in Michigan (May 2025), the 8th largest workforce among the 50 states and DC. The median wage is $38.56 an hour, 26% above the US median of $30.67.
Plumbers, pipefitters, and steamfitters make up about the same share of Michigan jobs as they do nationally (location quotient 1.07).
At a typical Michigan premium of about $1.66 per $100 of payroll (the published pure premium of $1.11 for class 5183 times a 1.5 carrier multiplier), comp on one worker at that wage costs about $0.64 for every hour worked, or $1,331 a year full time. A 2-person crew comes to roughly $2,663 a year in premium before any experience mod.
Because premium is charged on payroll, who you hire moves the bill. Michigan pay runs from $22.38 an hour at the 10th percentile to $49.73 at the 90th, so the same rate costs $0.37 an hour on a new hire and $0.83 on a senior hand.
Workers comp requirements in Michigan
- Coverage required: 3+ employees, or 1 employee working 35+ hours/week for 13+ weeks
- Owners and sole proprietors: Owners excluded for themselves; officers may exclude themselves if they own 10%+
- State fund: Private market (no state fund)
- Waiting period: 7 days; first week also retroactive if disability continues 14+ days
- Penalty for going without: Misdemeanor: up to $1,000 and/or 6 months jail, each day a separate offense
Michigan pays wage loss at 80% of after-tax average weekly wage, not the roughly two-thirds of gross most states use.
Michigan vs neighboring states
- Indiana: about $1.02 per $100 of payroll
- Ohio: about $1.46 per $100 of payroll
- Wisconsin: about $2.21 per $100 of payroll
Among its neighbors, Indiana is the cheapest for plumbing comp at $1.02 and Wisconsin the most expensive at $2.21 per $100 of payroll.
Working across the line into Ohio 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.