NCCI · 17 states

Workers comp rates for code 6503: Plumbing

NCCI class code 6503 covers Plumbing in the construction industry. The median rate across 17 states is $1.10 per $100 payroll. Rates range from $0.397 in Washington to $2.78 in Hawaii.

Also known as: Plumber · Plumbing contractor

Cheapest 5 states for code 6503

  1. Washington $0.397
  2. Utah $0.440
  3. Virginia $0.700
  4. Tennessee $0.740
  5. Kentucky $0.770

Most expensive 5 states

  1. Hawaii $2.78
  2. Illinois $2.66
  3. Nevada $1.78
  4. Alaska $1.71
  5. Rhode Island $1.40

What does NCCI class code 6503 cover?

Class code 6503 classifies employees performing Plumbing, also known as Plumber, Plumbing contractor. The NCCI classification system groups occupations by similar workplace exposure, loss-experience patterns, and operational characteristics. Code 6503 falls within the construction industry group and is filed in 17 states.

NCCI's governing classification rules state that a single-classification employer with at least 51% of payroll in this occupation generally classifies all employees under code 6503, with two standard exceptions: clerical office work (segregated payroll records required, reported under code 8810) and outside sales / collectors (code 8742). If your operation has multiple distinct activities, ask your underwriter about a multi-class split before accepting a single-code rating.

Why rates for code 6503 vary so widely across states

The rate spread for code 6503 is 7.0× from cheapest to most expensive ($0.397 in Washington to $2.78 in Hawaii). This isn't randomness, it reflects each state's claim experience for the occupation over the most-recent 5-year window NCCI uses, medical inflation in that state's hospital/clinic market, indemnity (lost-wage) cost levels driven by state maximum weekly benefit caps, and rating-bureau methodology. Independent-bureau states (California's WCIRB, New York's NYCIRB, Pennsylvania's PCRB, New Jersey's NJCRIB, Massachusetts's WCRIBMA, Delaware's DCRB, Wisconsin's WCRB, North Carolina's NCRB, Texas's TDI) often diverge significantly from NCCI's national pure premium, sometimes by 30% or more on the same occupation. Monopolistic-fund states (Ohio, North Dakota, Washington, Wyoming) don't allow private carrier competition, so the state fund's pricing is the only available option.

How to use this code 6503 rate data

  1. Benchmark your carrier quote. A carrier quoting code 6503 above the $1.40 75th-percentile rate is asking for a premium-rated quote, push back or get a second quote.
  2. Identify the right state filing. Use the table below to find your state's filed rate. If your carrier is quoting at a higher rate, the difference is either schedule debit, EMR, deductible loading, or a state-fund surcharge, ask which.
  3. Calculate your effective rate. Effective rate = base rate × EMR ± schedule credit/debit ± deductible loading. Two carriers quoting code 6503 at the same base can vary 30%+ on effective rate after these adjustments.
  4. Consider lower-rate states if locationally flexible. For code 6503, Washington ($0.397) is 86% cheaper than Hawaii ($2.78). Multi-state employers split payroll by state-of-work, not state-of-headquarters, so locating the high-payroll site in a cheaper state directly lowers premium.
  5. Build a 3-year EMR strategy. A 0.85 EMR cuts base rate by 15%; the difference between 0.85 and 1.25 EMR on the same code is a 47% premium difference. Frequency control (preventing every claim, even small ones) drives EMR more than severity control.

Code 6503 rates in all 17 states

State Code Rate per $100 vs peers Source
Washington monopolistic 6503 $0.397 6% view
Utah 6503 $0.440 12% view
Virginia 6503 $0.700 18% view
Tennessee 6503 $0.740 24% view
Kentucky 6503 $0.770 29% view
Kansas 6503 $0.830 35% view
Maryland 6503 $0.940 41% view
Louisiana 6503 $0.960 47% view
Indiana 6503 $1.10 53% view
Oklahoma 6503 $1.17 59% view
Arkansas 6503 $1.18 65% view
Alabama 6503 $1.34 71% view
Rhode Island 6503 $1.40 76% view
Alaska 6503 $1.71 82% view
Nevada 6503 $1.78 88% view
Illinois 6503 $2.66 94% view
Hawaii 6503 $2.78 100% view

Bottom quartile (cheap) Mid Top quartile (expensive)

What types of claims drive code 6503 rates?

Workers comp rate filings for code 6503 reflect what's actually happening on the job, not just generic occupation hazard. NCCI publishes loss-cost analyses showing which injury categories account for the bulk of indemnity (lost-wage) and medical claim cost. For Plumbing, the top drivers are typically:

  • Falls from elevation, OSHA's #1 cited construction hazard, drives 25-35% of indemnity claim cost in construction-class codes.
  • Struck-by and caught-between, including vehicle, equipment, and falling-object incidents, account for 15-20% of severity.
  • Cumulative trauma from repetitive lifting, overhead work, and awkward postures drives long-tail medical cost.
  • Electrical injuries, when present, are low-frequency but extreme-severity claims that disproportionately affect rate filings.

Targeting these drivers in your safety program produces the largest EMR improvement. Frequency control (preventing every claim, including small medical-only incidents) drives the modifier more than severity control. A documented written safety program addressing the top two drivers above is typically the highest-ROI intervention for employers paying for code 6503.

FAQs about NCCI 6503

What occupation is NCCI class code 6503?

Class code 6503 is "Plumbing" (also known as Plumber, Plumbing contractor), in the construction industry. The code is filed in 17 states.

What is the average workers comp rate for code 6503?

The median rate across 17 states is $1.10 per $100 of payroll, ranging from $0.397 (Washington) to $2.78 (Hawaii).

Why does code 6503 cost more in some states than others?

Workers comp rates reflect each state's loss experience for that occupation, the rating bureau's methodology (NCCI vs. independent), schedule rating credits, and the state's medical-cost inflation. Some states are monopolistic (only the state fund writes coverage) while others are open competitive markets.