Coverage description
A National Council on Compensation Insurance (NCCI) standard form. It sets how the premium is calculated when you choose a one-year retrospective rating plan, adjusting it after the policy year to the losses actually incurred, between a minimum and a maximum.
Updated
What the form says
Key clauses from edition D, the latest revision, quoted as filed.
“Retrospective rating plan premium is the sum of basic premium, converted losses, plus the excess loss premium”
WC 00 05 03 D
What the premium is made of. Basic premium is standard premium times a basic premium factor, and converted losses are your incurred losses, paid and reserved, times a loss conversion factor. That sum, plus any elective charges, is multiplied by the tax multiplier shown for each state.
“The charge for this loss limitation is called the excess loss premium.”
WC 00 05 03 D
What a loss limitation costs. If you elect a loss limitation, each accident, and each person's disease, counts in the formula only up to that amount. The cap is paid for through the excess loss premium: standard premium times an excess loss premium factor, times the loss conversion factor.
“will not be less than the minimum or more than the maximum retrospective rating plan premium”
WC 00 05 03 D
The floor and ceiling on the premium. However losses develop, the result stays between a minimum and a maximum premium. Each is standard premium multiplied by the minimum or maximum factor entered in the Schedule.
“using all loss information we have as of a date six months after the rating plan period ends and annually thereafter”
WC 00 05 03 D
When the premium is calculated. The first calculation uses losses valued six months after the one-year plan period ends, and it is redone each year after that, with a refund or an additional bill each time, until you and the insurer agree a calculation is final. The optional retrospective development premium is charged only with the first three calculations.
How the form has changed
1 change across 1 revision, newest first. Each edition is compared with the one before it, using wording from filed copies.
Edition D
Compared with edition CLatest editionRenames the third component of the basic premium factor from insurance charge to net aggregate loss factor. The formula and the other provisions are unchanged.
Edition C
“Insurance charge”
Edition D
“Net aggregate loss factor”
Editions
Revision letters as filed, newest first. Filing counts include every state submission that lists the edition.
| Edition | Filings | Companies | States | Filed | Document |
|---|---|---|---|---|---|
| DLatest | 67 | 46 | 10 | Nov 2021 to Sep 2026 | View PDF |
| C | 29 | 35 | 6 | May 2022 to Jul 2026 | View PDF |
| B | 5 | 5 | 1 | Mar 2022 to Jun 2026 | View PDF |
2 other edition dates appear in one or two filings each, often carrier-specific versions: A, Original.
What the filings show
- Edition in use: in the past 12 months, 17 companies filed edition D and 12 companies filed edition C.
- WC 00 05 04 (Retrospective Rating Plan Premium Endorsement Three-Year Plan) is filed alongside it most often, in 96 of the same filings (95%).
Filed under
Data from admitted P&C filings with state insurance departments, submitted Nov 2021 to Sep 2026, excluding withdrawn and rejected filings. One filing can cover several affiliated companies.
Carriers filing this form
The 10 carrier groups with the most filings that include WC 00 05 03, out of 27 in total.
| Carrier | Filings | States | Editions, most filed first | Last filed |
|---|---|---|---|---|
| Brookfield Wealth Solutions Group4 group companies filed it, led by Argonaut Insurance Company and Argonaut-Midwest Insurance Company | 19 | 1 | D | Jun 4, 2026 |
| Nationwide Corporation Group3 group companies filed it, led by Crestbrook Insurance Company and National Casualty Company | 10 | 1 | CD | Jun 30, 2026 |
| AXA Insurance Group5 group companies filed it, led by Greenwich Insurance Company and XL Insurance America, Inc. | 6 | 2 | BD | Jun 23, 2026 |
| Acuity, A Mutual Insurance Company | 6 | 2 | CD | Jul 1, 2026 |
| Sompo Group2 group companies filed it, led by Sompo America Fire and Marine Insurance Company and Sompo America Insurance Company | 6 | 2 | D | Jun 15, 2026 |
| Tokio Marine Holdings Incorporated Group2 group companies filed it, led by Safety First Insurance Company and Safety National Casualty Corporation | 6 | 2 | D | May 14, 2025 |
| Louisiana Workers Compensation GroupPrescient National Insurance Company | 5 | 2 | DOriginal | Jul 2, 2025 |
| RLI Insurance GroupRLI Insurance Company | 5 | 1 | D | Aug 18, 2026 |
| THE Hanover Insurance Group6 group companies filed it, led by Allmerica Financial Alliance Insurance Company and Allmerica Financial Benefit Insurance Company | 5 | 1 | C | Jun 23, 2026 |
| Arch Insurance Group2 group companies filed it, led by Arch Indemnity Insurance Company and Arch Insurance Company | 4 | 1 | D | Apr 8, 2026 |
How the largest insurers handle WC 00 05 03
Groups among the largest workers compensation insurers that filed WC 00 05 03 or their own version in the past five years.
- Amtrust Financial Services GroupFiles its own version: WC 21 0503 D Retrospective Rating Plan Premium Endorsement One Year Plan (1 state)
States
Number of filings that include WC 00 05 03 in each state, Nov 2021 to Sep 2026. Darker states have more filings.
Often filed with
Standard-style form numbers that appear in the same filings most often.
- WC 00 05 04Retrospective Rating Plan Premium Endorsement Three-Year Plan96 filings
- WC 00 05 05Retrospective Rating Plan Premium Endorsement Wrap-Up Construction Project95 filings
- WC 00 04 19Premium Due Date Endorsement92 filings
- WC 00 04 22Terrorism Risk Insurance Program Reauthorization Act Disclosure Endorsement91 filings
- WC 00 05 10Retrospective Rating Plan Premium Endorsement Non-Ratable Catastrophe Element or Surcharge91 filings
- WC 00 01 06Longshoremen's and Harbor Workers' Compensation Act Coverage Endorsement90 filings
- WC 00 01 11Migrant and Seasonal Agricultural Worker Protection Act Coverage90 filings
- WC 00 03 04Insurance Company as Insured Endorsement90 filings
- WC 00 03 05Joint Venture as Insured Endorsement90 filings
- WC 00 03 15Domestic and Agricultural Workers Exclusion Endorsement90 filings
Recent filings
Latest filings that include this form number. Filed copies open in FilingFocus.
| Submitted | Company | State | Editions | Tracking number |
|---|---|---|---|---|
| Sep 16, 2026 | ZNAT Insurance Company | CT | D | ZICO-135090521 |
| Aug 18, 2026 | RLI Insurance Company | CO | D | RLSC-135057018 |
| Jul 1, 2026 | Acuity, A Mutual Insurance Company | CO | C | ACUT-134982793 |
| Jun 30, 2026 | American Casualty Company of Reading, Pennsylvaniaand 5 more | CO | D | CNAB-135003197 |
| Jun 30, 2026 | Crestbrook Insurance Companyand 1 more | CO | C | NWPP-135003409 |
| Jun 30, 2026 | National Casualty Company | CO | D | NWPP-135004216 |
| Jun 23, 2026 | Allmerica Financial Alliance Insurance Companyand 5 more | CO | C | HNVX-134968029 |
| Jun 23, 2026 | AXA XL Insurance Company Americasand 3 more | CO | B | XLAM-134996276 |
| Jun 15, 2026 | Sompo America Fire and Marine Insurance Companyand 1 more | CO | D | SMPJ-134970923 |
| Jun 4, 2026 | Argonaut-Midwest Insurance Company | CO | D | ARGN-134974739 |
| Jun 4, 2026 | Argonaut Insurance Company | CO | D | ARGN-134974742 |
| Jun 4, 2026 | Rockwood Casualty Insurance Company | CO | D | ARGN-134974764 |
Most filed NCCI WC forms
- WC 00 00 01 Information Page
- WC 00 04 19 Part Five, Premium Amendatory Endorsement
- WC 00 00 00 Workers Compensation and Employers Liability Insurance Policy
- WC 00 04 21 Catastrophe (Other Than Certified Acts of Terrorism) Premium Endorsement
- WC 00 04 06 Premium Discount Endorsement
- WC 00 03 13 Waiver of Our Right to Recover From Others Endorsement
- WC 00 04 22 Terrorism Risk Insurance Program Reauthorization Act Disclosure Endorsement
- WC 00 03 08 Partners, Officers and Others Exclusion Endorsement
- WC 00 03 03 Employers Liability Coverage Endorsement
- WC 00 03 11 Voluntary Compensation and Employers Liability Coverage Endorsement
- WC 00 04 03 Experience Rating Modification Factor Endorsement
- WC 00 04 04 Pending Rate Change Endorsement