WCRates

Rate Methodology & Data Sources

Last reviewed:

Since 12 October 2026 WorkersCompCost.com publishes two kinds of number, and only one of them is in dollars. A filed figure is copied from a state regulator’s or rating bureau’s own filing, with the filing and its effective date beside it. A cost index ranks a state against the median state; it is modelled and it is not a price. Neither is a quote. This page documents both, and the measurement that made us stop publishing modelled per-$100 estimates.

The short version

  • States whose filings we publish (4): every class figure is the filed loss cost or rate exactly as the publisher printed it. A loss cost is not a rate — the insurer multiplies it by its own loss cost multiplier — and each page says which one it is showing.
  • Every other state: no dollar figure at all. The page shows the state’s cost index (median state = 1.00) and, for each class code, the filed figures of the states that do publish them.
  • Monopolistic state funds (Ohio, North Dakota, Washington, Wyoming): the fund’s own pricing model, and Ohio BWC’s own filed base rates.

Filed figures — the states whose filings we publish

These tables are transcribed from the publisher’s own document and are not modelled; the data modules that hold them cannot import the site’s model, and a build check fails if a transcribed value stops matching the recorded spot checks.

  • Delaware — Delaware Compensation Rating Bureau loss costs, Amended Filing No. 2501 (Circular No. 1062), effective 2025-12-01; 595 classes, in the state's own class codes (shown on the state page only, never against an NCCI number). Source (retrieved 2026-10-12)
  • New York — New York Compensation Insurance Rating Board loss costs, Bulletin R.C. 2659, Exhibit A, effective 2026-10-01; 504 classes. Source (retrieved 2026-10-12)
  • Pennsylvania — Pennsylvania Compensation Rating Bureau loss costs, Filing No. C-387 (Circular No. 1840), effective 2026-04-01; 607 classes, in the state's own class codes (shown on the state page only, never against an NCCI number). Source (retrieved 2026-10-12)
  • Wisconsin — Wisconsin Compensation Rating Bureau manual rates, General Circular Letter 3273 (October 1, 2026 rate revision), effective 2026-10-01; 474 classes. Source (retrieved 2026-10-12)

Why not every state? In most NCCI states the per-class loss costs are NCCI’s licensed pages. Regulators such as the Texas Department of Insurance and Alaska’s Division of Insurance post them, but under a notice that the material may not be copied or displayed without NCCI’s written permission, so we link to the regulator’s copy from the state page instead of republishing it. Bureaus that print their own copyright on the filing itself are held back for the same reason until the terms are confirmed, and some bureaus publish their per-class tables only to members.

The cost index — how states are compared

Each of the 47 jurisdictions rated on NCCI-style class codes carries a state cost multiplier. The cost index divides it by the median multiplier across those jurisdictions:

cost index = state multiplier ÷ median state multiplier (median state = 1.00)

The multipliers began in April 2026 as plausibility estimates of each state’s relative cost level and are carried forward by the statewide average change of every filing that state has made since — New York’s −21.9% on 1 October 2026, for example. They are not reconciled to filed loss costs class by class, so the index is the same for every class code in a state and says nothing about how one class compares with another. That is why it is printed as a ratio and never as a price.

Where the class-code pages give a code a class percentile of, say, 60 (out of 100), that position is computed only from the filed tables above — never from the model, whose ordering of classes agreed with the filings at a rank correlation of only about 0.7.

To turn any rate into a premium, the premium calculator uses annual payroll ÷ 100 × rate × experience modifier. It pre-fills the rate only from a filed figure; otherwise you enter the rate on your own quote.

How well calibrated the retired estimates were — and why they were retired

Until 12 October 2026 this site published a modelled per-$100 figure for every state and class code: a national base rate for the class multiplied by the state’s multiplier. We measured those figures against every regulator or bureau table we could retrieve, and they did not hold up.

  • Georgia (August 2026) — against the advisory loss costs the State Board of Workers’ Compensation publishes, across 170 shared codes: a median 2.3 times the filed loss cost; only 10% within 25% of it.
  • Texas (August 2026) — TDI publishes a 1 July 2026 loss cost for code 5551 (Roofing) of 1.946; the model gave 18.75, about ten times as much.
  • New York (October 2026) — against NYCIRB’s October 1, 2026 loss costs across 155 shared codes: a median 2.5 times the filed figure; 14% within 25%.
  • Wisconsin (October 2026) — against WCRB’s October 1, 2026 manual rates, which include expenses, across 169 shared codes: a median 1.8 times the filed rate; 14% within 25%.

The error was in the national base rates, not the state multipliers, and it was not a uniform offset that one correction factor could remove: the model put classes in the same order as the filings at a rank correlation of only about 0.7. So the base rates were retired rather than re-tuned. Today every dollar figure on the site is a transcription, which means that for the states whose filings we publish the published figure equals the filed one by construction, and every other state shows the relative index only.

For a figure you can rely on in a state we do not transcribe, use the state bureau’s own published loss costs, linked from the state page, or a quote from a licensed agent.

Where the numbers come from

The bodies that govern each jurisdiction, and whose filings every dated fact on this site is checked against, are:

Each state page links to the specific bureau or filing it cites. Independent-bureau states are never conflated with NCCI loss costs. Bureau links above were last verified 2026-07-09. The full directory of workers’ comp rating bureaus by state covers the remaining independent bureaus, including Michigan (CAOM), Indiana (ICRB), Minnesota (MWCIA), Wisconsin (WCRB) and Massachusetts (WCRIBMA).

How often the data is refreshed

Most states refile loss costs or rates annually, on staggered effective dates — for example Florida on January 1, California on September 1 and New York and Wisconsin on October 1. We re-verify state filing dates, bureau classifications and the transcribed filed tables on a rolling schedule, stamp each state and class-code page with a visible “last verified” date, and carry each state’s cost multiplier forward by the statewide average change of its new filing once it takes effect.

What re-verification covers: which bureau governs a state, the coverage threshold, the effective date of the filing in force, and — for the states whose filings we publish — the transcribed per-class figures themselves.

Limitations — read before relying on a figure

  • A filed loss cost is not what you pay: your insurer multiplies it by its own loss cost multiplier. A filed rate is closer, but premium still depends on your experience modifier, payroll audit, schedule rating, minimum premium and assessments.
  • The cost index is a modelled relative position, the same for every class code in a state. It is not a price and cannot be multiplied into one.
  • A state’s class wording can differ from NCCI’s for the same number — check the state manual before relying on a match.
  • Class-code assignment is governed by the applicable scopes manual and should be confirmed with your carrier or a licensed agent.

For the full legal disclaimer, see our disclaimer page. This page is informational and is not insurance, legal, or financial advice.

Spotted something off?

We take data accuracy seriously. If a filed figure, cost index, effective date, or bureau classification looks wrong, check the source filing linked on the relevant state or class-code page — and let us know via the contact details on that page.