Delaware Plumbing Workers Comp Rates (2026)
The published Delaware loss cost for plumbing workers comp, class 0663 (Plumbing: Gas, Steam, Hot Water or Other Pipefitting, Including House Connections), is $1.670 per $100 of payroll (effective December 1, 2025). Carriers multiply it by their own filed multiplier, so a typical premium is about $2.50.
A loss cost 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.
Delaware class code for plumbing
- 0663: Plumbing: Gas, Steam, Hot Water or Other Pipefitting, Including House Connections
Delaware uses its own classification codes (largely the same numbering as Pennsylvania, e.g. 659 Roofing) and gives construction employers a wage-based premium credit through the Delaware Construction Classification Premium Adjustment Program instead of using NCCI codes.
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 Delaware
The Bureau of Labor Statistics counts 1,590 plumbers, pipefitters, and steamfitters on payrolls in Delaware (May 2025), the 47th largest workforce among the 50 states and DC. The median wage is $31.11 an hour, in line with the US median of $30.67.
Plumbers, pipefitters, and steamfitters make up about the same share of Delaware jobs as they do nationally (location quotient 1.10).
At a typical Delaware premium of about $2.50 per $100 of payroll (the published loss cost of $1.67 for class 0663 times a 1.5 carrier multiplier), comp on one worker at that wage costs about $0.78 for every hour worked, or $1,618 a year full time. A 2-person crew comes to roughly $3,235 a year in premium before any experience mod.
Because premium is charged on payroll, who you hire moves the bill. Delaware pay runs from $19.71 an hour at the 10th percentile to $45.93 at the 90th, so the same rate costs $0.49 an hour on a new hire and $1.15 on a senior hand.
Workers comp requirements in Delaware
- Coverage required: 1 employee; construction workers cannot be classified as independent contractors
- Owners and sole proprietors: Excluded by default; may elect in
- State fund: Private market (Delaware Compensation Rating Bureau residual market)
- Waiting period: 3 days; retroactive from day one if disability reaches 7 days
- Penalty for going without: Fine up to three times the annual premium owed, plus $10 per employee per day
Delaware statutorily deems construction crews employees, so they cannot be 1099'd out of the coverage mandate.
Delaware vs neighboring states
- New Jersey: about $4.46 per $100 of payroll
- Pennsylvania: about $2.47 per $100 of payroll
Among its neighbors, Pennsylvania is the cheapest for plumbing comp at $2.47 and New Jersey the most expensive at $4.46 per $100 of payroll.
If your crews work across the line, list those states under item 3.A or 3.C of your policy before the job starts. Rates follow the state where the work is done, not where your office is.
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.