NCCI loss costs and carrier multipliers: why two carriers quote different manual rates for the same class code

Put the same account in front of two carriers and you can get two different manual rates for the identical class code — before the mod, before schedule credits, before anything negotiable. Brokers see this daily and most explain it with a shrug: "different carriers, different rates." The real mechanics are more useful than the shrug, because once you know where a manual rate comes from, you can check it, predict it, and argue with it.

The two-piece rate

In most states, workers' comp rating starts with a bureau — NCCI in the majority of them — that files advisory loss costs by class code. A loss cost is the bureau's estimate of pure loss: the expected claim dollars (and loss adjustment expense) per $100 of payroll for that classification, built from the aggregated loss experience every carrier reports.

What a loss cost deliberately excludes is everything else an insurer needs: overhead, commissions, taxes, profit, and that carrier's own view of the class. Each carrier adds those by filing its own loss cost multiplier (LCM) — a factor applied to the bureau's loss cost:

Advisory loss cost  ×  carrier LCM  =  carrier manual rate (per $100 of payroll)
Manual rate  ×  (payroll ÷ 100)    =  manual premium

An illustrative example (not filed figures): if the bureau's loss cost for a warehouse class is 3.80 and Carrier A files a 1.30 LCM while Carrier B files 1.65, Carrier A's manual rate is 4.94 and Carrier B's is 6.27 — a 27% gap on identical payroll, created entirely by two filed multipliers. On $2 million of class payroll that is $98,800 versus $125,400 of manual premium before any account-specific factor is applied.

What an LCM actually tells you

An LCM is a carrier talking about itself. Inside it are the carrier's expense ratio, its profit load, and — most useful to a broker — its appetite. Three readable signals:

• Level. A carrier filing a low multiplier is pricing to grow; a high one is pricing to shrink or to select.
• Tiering. Many carriers file multiple rating tiers — in effect several LCMs — and assign accounts to a tier by underwriting criteria. Two quotes from the same carrier can carry different manual rates because the account landed in different tiers. When a renewal quote jumps with no loss change, the first question is whether the account was re-tiered.
• Movement. A carrier that refiles its LCM upward mid-year is repricing its whole book. Seeing the filing before renewal tells you what the incumbent will do months before the quote arrives.

All of this is public. LCM filings sit in each state's SERFF filing-access system, searchable by carrier. (How to pull one.)

The timing rule that prevents mispricing

A quote must be priced on the loss costs and LCM in effect on the policy effective date — the most recent filing with an effective date on or before it, never a future-effective filing. It sounds pedantic until a bureau files new loss costs effective April 1 and you're pricing a March 15 renewal: use the new filing and every class rate is wrong. The same discipline applies historically — a quote generated last year should be reproducible from the filings that were effective then, which is why our rate engine snapshots the loss cost and LCM onto every quote rather than re-deriving them later.

California is different

California has no NCCI loss costs. The WCIRB — the state's own rating bureau — publishes advisory pure premium rates, and carriers file their own rates informed by them. If a tool or a worksheet applies "NCCI loss cost × LCM" to a California class code, the California numbers are wrong by construction. Multi-state accounts need per-bureau logic, not one formula.

How to use this on a live account

1. Decompose every quote. Divide the quoted manual rate by the bureau loss cost for that class and state: the result is the effective multiplier the carrier applied. Do it per class — if the implied multiplier differs across classes on one quote, you're looking at tiering or an error worth a question.
2. Compare carriers before submitting. Filed LCMs tell you who is priced to win a class before you spend a submission on a carrier priced to decline it.
3. Check the dates. Quote effective date against filing effective dates, both bureau and carrier.
4. Watch the refile. An incumbent's new LCM filing is your renewal forecast.

HALO IQ's CarrierIQ ingests bureau loss costs and carrier LCM filings from SERFF and computes manual rates by class, state, and tier — with staleness flags when a filing you priced on has been superseded. See your states' current filings.

Rates and multipliers above are illustrative. Actual loss costs and LCMs are public filings — cite the filing, not a blog post, when you price.