What California's September 1, 2026 Experience Rating Changes Do to Your X-Mod
- Evan Swan
- 4 days ago
- 6 min read
Quick answer: what changes for California experience rating on September 1, 2026
Three amendments to California's Experience Rating Plan take effect for rating dates on or after September 1, 2026. The eligibility threshold rises from $10,800 to $11,700 in expected losses, which drops some small employers out of experience rating entirely. Table I (Expected Loss Rates and D-Ratios) and Table II (Primary Thresholds) were both updated to current data, and expected loss rates are now published to three decimal places.
Source: WCIRB September 1, 2026 Regulatory Filing Quick Reference Guide. Verified August 4, 2026 by CPR Business Solutions, a wholesale workers' comp MGA specializing in high-mod placement.
Most of the attention on September 1 is going to the dual-wage thresholds and the 10.4% pure premium increase, because those are easy to explain and land on an invoice. The Experience Rating Plan changes are quieter and, for some accounts, worth more money.
Here is what actually changed, what each piece does mechanically, and — importantly — what the WCIRB's summary does not tell you.
1. The eligibility threshold rises to $11,700
Section III, Rule 1 of the Experience Rating Plan was amended to move the eligibility threshold from $10,800 to $11,700, to reflect wage inflation and the new September 1, 2026 expected loss rates.
In plain terms: to be experience rated in California, an employer's expected losses over the experience period have to clear a floor. That floor just went up by $900. An employer sitting just above the old floor may now sit below the new one — and an employer that isn't experience rated doesn't have an X-Mod at all. They're rated at manual rates.
This is the change most likely to surprise someone, and it cuts both ways depending on which side of 1.00 the account sits:
A clean account loses its credit. A small employer with a 0.82 mod has been paying 18% below manual. Fall out of eligibility and they pay manual — an 18% increase on the same payroll and the same clean loss history. Nothing about the risk changed; they simply got too small to be rated on their own experience.
A distressed account loses its debit. The mirror image, and it is worth actively checking for. A small employer carrying a 1.70 mod who drops below the eligibility floor goes to manual rates — a 41% reduction against what they were paying, with no loss-control work required. If you have a small California account with an ugly mod, run the eligibility calculation before the September renewal.
One caution on that second point: eligibility is not a lever you control by shrinking payroll, and nobody should be managing headcount to dodge a mod. But when an account is already near the line, knowing which side it lands on before you market it is the difference between a competitive quote and a surprise.
2. Expected Loss Rates and D-Ratios updated — now to three decimals
Table I was amended to reflect the most current data available, and the Expected Loss Rates are now shown at three decimal places rather than two.
The Expected Loss Rate is what the formula thinks a business of your size, in your class code, should lose per $100 of payroll. Your actual losses are measured against that expectation. Change the ELR and you change the denominator of the comparison — which moves the mod even if the employer's claims are identical year over year.
The D-Ratio is the companion figure: the share of expected losses assumed to fall in the primary (heavily weighted) layer. It's the reason two employers with identical total losses can carry different mods.
The move to three decimals sounds cosmetic and mostly is — but it reduces rounding drift on large-payroll accounts, where a rounding difference in the second decimal could shift expected losses by a meaningful amount. If you have ever recalculated a client's mod by hand and landed a point or two away from the published figure, this is one of the reasons why.
3. Primary Thresholds updated
Table II was also amended to reflect current data. The primary threshold is the dividing line between the primary and excess portions of each claim. Dollars below it carry full weight in the mod formula; dollars above it are heavily discounted.
This is the single most important mechanic in experience rating, and the one that explains the counterintuitive result most clients get wrong: the formula punishes frequency far more than severity. Ten $3,000 claims sit entirely in the primary layer at full weight. One $30,000 claim puts most of its value in the lightly-weighted excess layer. Same total dollars, very different mod.
Raising a primary threshold pulls more of each claim into the full-weight layer, which pushes mods up for frequency-driven accounts. Lowering it does the reverse.
Being straight about the limits of what's published: the WCIRB's summary states that Table II was amended to reflect current data. It does not state a direction, and primary thresholds in California vary by expected-loss size rather than sitting at one universal figure. Anyone telling you flatly that "mods are going up on September 1" because of the primary threshold is asserting more than the published summary supports. The honest answer is that the table moved, the direction varies by account size, and the only way to know what happened to a specific client is to look at their worksheet.
The payroll limitation changes that land alongside
The same filing amended payroll minimums and maximums under the Uniform Statistical Reporting Plan. The one that touches the most accounts:
Executive officers, partners, individual employers and LLC members — payroll minimum $66,300, maximum $171,600.
A long list of professional and clerical classifications — including law firms (8820), insurance companies (8822), banks (8808), physicians' practices (8834), hospitals (9043), engineers (8601) and software development (8859) — carry a $171,600 payroll maximum per employee.
Taxicab operations (7365) — $46,900 payroll minimum. Department stores (8039) — $1,400,000 payroll minimum.
Payroll limitations matter to the mod, not just the premium: capped payroll flows into the expected-loss calculation, so an officer's payroll cap changes the denominator too.
Three classifications were also eliminated and their operations reassigned: 2102 (fruit or vegetable evaporation) and 2111(3) (pickling) both fold into 2111(1), and 3070 (computer memory disk manufacturing) folds into 3681(2). If you write an account in one of those, the class code on the renewal will change even though nothing about the operation did.
What this means for a hard California account
Layer these changes onto a distressed account and the picture gets busy fast. A California contractor with a 1.65 mod renewing in September could be facing a dual-wage reclassification on part of their crew, a 10.4% pure premium increase, and a mod that moved on updated tables — all at once, none of which reflects anything the business did differently.
That compounding is the argument for re-marketing rather than renewing on autopilot. It's also worth remembering the wider context: California's 2025 accident-year combined ratio came in around 129 while the state represents roughly a fifth of the national market. Carriers know California is running unprofitably, which is why rates are moving — and why appetite for hard California risk tightens faster here than anywhere else.
What to actually do before a September renewal
Pull the current mod worksheet — not just the mod. The worksheet shows expected losses, the primary/excess split, and which claims are driving the number.
Check expected losses against the new $11,700 eligibility floor. If the account is near it, find out which side it lands on before you market.
Recalculate on the new tables rather than assuming last year's mod carries forward.
Cross-check the dual-wage split at the same time if the client is in construction — the threshold tracker has every class code.
Verify officer payroll is being reported inside the $66,300–$171,600 band.
Budget the 10.4% pure premium increase on top of all of it.
Where the numbers came from
Every figure on this page is taken from the WCIRB's own September 1, 2026 Regulatory Filing Quick Reference Guide, which summarizes the amendments approved by the Insurance Commissioner. Where the WCIRB's summary doesn't state something — notably the direction of the primary threshold change — we've said so rather than filling the gap. For the full regulations, see the Experience Rating Plan and Uniform Statistical Reporting Plan themselves.
Placing California accounts through the change
CPR Business Solutions is a wholesale workers' compensation MGA placing hard-to-write California accounts since 2021 — high experience mods, hazardous class codes, PEO co-employment, and accounts coming out of State Fund or assigned risk. If a September renewal is about to reprice and you want a second read on the mod before it binds, send it over.
Submit an account at proposals@cprbrokers.com or call (704) 256-5945.
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