Coverage description
A National Council on Compensation Insurance (NCCI) standard form. It applies a contingent experience rating modification factor, based on the experience data available, that replaces any prior factor and stays in force unless the insurer issues a revised one.
Updated
What the form says
Key clauses from the original edition, which has not been revised, quoted as filed.
“based on the appropriate experience data available and replaces any prior experience modification factor”
WC 00 04 12
What the scheduled factor is. The factor in the schedule is a contingent one, built from the experience data available when the endorsement is issued, and it takes the place of any modification factor applied to the policy before.
“We will issue an endorsement to show a revised factor if appropriate additional experience data becomes available.”
WC 00 04 12
When the factor can be revised. If more experience data becomes available, the insurer issues a further endorsement showing the revised factor.
“The contingent factor will apply unless a revised factor is subsequently issued.”
WC 00 04 12
Which factor applies in the meantime. Premium is adjusted by the contingent factor unless a revised factor is later issued. The form sets no deadline for a revision.
How the form has changed
Filed copies carry the original 1-90 edition, with no revision letter.
Editions
Edition dates as filed, newest first. Filing counts include every state submission that lists the edition.
| Edition | Filings | Companies | States | Filed | Document |
|---|---|---|---|---|---|
| OriginalLatest | 153 | 83 | 26 | Dec 2021 to Sep 2026 | View PDF |
What the filings show
- Edition in use: in the past 12 months, 57 companies filed the original edition.
- WC 00 04 03 (Experience Rating Modification Factor Endorsement) is filed alongside it most often, in 150 of the same filings (98%).
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Data from admitted P&C filings with state insurance departments, submitted Nov 2021 to Sep 2026, excluding withdrawn and rejected filings.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 04 12, out of 32 in total.
| Carrier | Filings | States | Editions, most filed first | Last filed |
|---|---|---|---|---|
| Brookfield Wealth Solutions Group5 group companies filed it, led by Argonaut Insurance Company and Argonaut-Midwest Insurance Company | 20 | 1 | Original | Jun 25, 2026 |
| Nationwide Corporation Group9 group companies filed it, led by AMCO Insurance Company and Crestbrook Insurance Company | 20 | 1 | Original | Jun 30, 2026 |
| United Fire & CAS GroupUnited Fire and Casualty Company | 15 | 12 | Original | May 4, 2026 |
| AXA Insurance Group5 group companies filed it, led by Greenwich Insurance Company and XL Insurance America, Inc. | 6 | 2 | Original | Jun 23, 2026 |
| Acuity, A Mutual Insurance Company | 6 | 2 | Original | Jul 1, 2026 |
| Tokio Marine Holdings Incorporated Group2 group companies filed it, led by Safety First Insurance Company and Safety National Casualty Corporation | 6 | 2 | Original | May 14, 2025 |
| Intact Financial Group3 group companies filed it, led by Atlantic Specialty Insurance Company and OBI America Insurance Company | 5 | 1 | Original | Jun 24, 2026 |
| Mutual Capital Group Incorporated GroupIllinois Casualty Company | 5 | 5 | Original | Oct 30, 2025 |
| RLI Insurance GroupRLI Insurance Company | 5 | 1 | Original | Aug 18, 2026 |
| Sompo Group2 group companies filed it, led by Sompo America Fire and Marine Insurance Company and Sompo America Insurance Company | 5 | 1 | Original | Jun 15, 2026 |
States
Number of filings that include WC 00 04 12 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 04 03Experience Rating Modification Factor Endorsement150 filings
- WC 00 03 10Sole Proprietors, Partners, Officers and Others Coverage Endorsement148 filings
- WC 00 04 22Terrorism Risk Insurance Program Reauthorization Act Disclosure Endorsement148 filings
- WC 00 03 08Partners, Officers and Others Exclusion Endorsement147 filings
- WC 00 04 21Catastrophe (Other Than Certified Acts of Terrorism) Premium Endorsement147 filings
- WC 00 04 14Notification of Change in Ownership Endorsement146 filings
- WC 00 03 13Waiver of Our Right to Recover From Others Endorsement145 filings
- WC 00 04 06Premium Discount Endorsement143 filings
- WC 00 04 19Premium Due Date Endorsement143 filings
- WC 00 00 00Workers Compensation and Employers Liability Insurance Policy142 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 | Original | ZICO-135090521 |
| Aug 18, 2026 | RLI Insurance Company | CO | Original | RLSC-135057018 |
| Jul 1, 2026 | Acuity, A Mutual Insurance Company | CO | Original | ACUT-134982793 |
| Jun 30, 2026 | American Casualty Company of Reading, Pennsylvaniaand 5 more | CO | Original | CNAB-135003197 |
| Jun 30, 2026 | Crestbrook Insurance Companyand 1 more | CO | Original | NWPP-135003409 |
| Jun 30, 2026 | National Casualty Company | CO | Original | NWPP-135004216 |
| Jun 25, 2026 | American National Property And Casualty Company | CO | Original | ANPC-134996042 |
| Jun 24, 2026 | Atlantic Specialty Insurance Companyand 2 more | CO | Original | BEAC-134978198 |
| Jun 23, 2026 | Allmerica Financial Alliance Insurance Companyand 5 more | CO | Original | HNVX-134968029 |
| Jun 23, 2026 | AXA XL Insurance Company Americasand 3 more | CO | Original | XLAM-134996276 |
| Jun 15, 2026 | Sompo America Fire and Marine Insurance Companyand 1 more | CO | Original | SMPJ-134970923 |
| Jun 12, 2026 | All America Insurance Companyand 1 more | CO | Original | CEMC-134982050 |
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