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NCCI endorsement · workers compensation

WC 00 04 25 Experience Rating Modification Factor Revision Endorsement

Filings
141
latest Nov 2, 2026
Filing companies
78
34 carrier groups
States
26
Latest edition
Original
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Coverage description

A National Council on Compensation Insurance (NCCI) standard form. It tells the insured that the experience rating modification factor on the information page can be revised under the insurer's manuals and applied to the policy, with an endorsement showing any new factor.

Updated

What the form says

Key clauses from the original edition, which has not been revised, quoted as filed.

“The premium for the policy is adjusted by an experience rating modification factor”

WC 00 04 25

Premium is experience rated. The policy premium is adjusted by the employer's experience modification, which reflects its own loss history against the losses expected for its classifications.

“may be revised and applied to the policy in accordance with our manuals and endorsements”

WC 00 04 25

The factor can change after the policy starts. The factor shown at the start is not final. A revised modification can be applied to the current policy under the rating rules.

“We will issue an endorsement to show the revised factor, if different from the factor shown, when it is calculated”

WC 00 04 25

How a revised factor is shown. The insurer issues an endorsement only when the new factor differs from the one on the information page, and does so once the factor is calculated.

How the form has changed

WC 00 04 25 has a single edition, 5-17, with no lettered revision.

Editions

Edition dates as filed, newest first. Filing counts include every state submission that lists the edition.

EditionFilingsCompaniesStatesFiledDocument
OriginalLatest1417826Dec 2021 to Nov 2026View PDF

What the filings show

  • Edition in use: in the past 12 months, 49 companies filed the original edition.
  • WC 00 04 21 (Catastrophe (Other Than Certified Acts of Terrorism) Premium Endorsement) is filed alongside it most often, in 136 of the same filings (96%).

Filed under

Standard WC 121WC 16Employers Liability WC 4

Data from admitted P&C filings with state insurance departments, submitted Nov 2021 to Nov 2026, excluding withdrawn and rejected filings.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 25, out of 34 in total.

CarrierFilingsStatesEditions, most filed firstLast filed
Nationwide Corporation Group9 group companies filed it, led by AMCO Insurance Company and Crestbrook Insurance Company201OriginalJun 30, 2026
Brookfield Wealth Solutions Group4 group companies filed it, led by Argonaut Insurance Company and Argonaut-Midwest Insurance Company191OriginalJun 4, 2026
United Fire & CAS GroupUnited Fire and Casualty Company1512OriginalMay 4, 2026
Acuity, A Mutual Insurance Company62OriginalJul 1, 2026
Intact Financial Group3 group companies filed it, led by Atlantic Specialty Insurance Company and OBI America Insurance Company51OriginalJun 24, 2026
Mutual Capital Group Incorporated GroupIllinois Casualty Company55OriginalNov 2, 2026
RLI Insurance GroupRLI Insurance Company51OriginalAug 18, 2026
State Farm GroupState Farm Fire and Casualty Company51OriginalMay 4, 2026
THE Hanover Insurance Group6 group companies filed it, led by Allmerica Financial Alliance Insurance Company and Allmerica Financial Benefit Insurance Company51OriginalJun 23, 2026
Arch Insurance Group2 group companies filed it, led by Arch Indemnity Insurance Company and Arch Insurance Company41OriginalApr 8, 2026

View all 34 carrier groups

How the largest insurers handle WC 00 04 25

Groups among the largest workers compensation insurers that filed WC 00 04 25 or their own version in the past five years.

States

Number of filings that include WC 00 04 25 in each state, Nov 2021 to Nov 2026. Darker states have more filings.

Tennessee: 1 filingTN1Alabama: 1 filingAL1Florida: 0 filingsFLGeorgia: 4 filingsGA4Oklahoma: 3 filingsOK3South Carolina: 3 filingsSC3Arkansas: 0 filingsARMissouri: 1 filingMO1Indiana: 1 filingIN1Louisiana: 2 filingsLA2Ohio: 0 filingsOHWisconsin: 0 filingsWITexas: 0 filingsTXKentucky: 2 filingsKY2Iowa: 0 filingsIAKansas: 0 filingsKSMississippi: 1 filingMS1North Carolina: 0 filingsNCNebraska: 0 filingsNESouth Dakota: 1 filingSD1Montana: 2 filingsMT2New Hampshire: 0 filingsNHVirginia: 0 filingsVAArizona: 3 filingsAZ3Pennsylvania: 1 filingPA1Rhode Island: 0 filingsRIMichigan: 4 filingsMI4Alaska: 0 filingsAKDistrict of Columbia: 0 filingsDCIdaho: 1 filingID1Maryland: 0 filingsMDWest Virginia: 0 filingsWVUtah: 2 filingsUT2Wyoming: 0 filingsWYDelaware: 0 filingsDENew Mexico: 2 filingsNM2Colorado: 98 filingsCO98Connecticut: 1 filingCT1Maine: 0 filingsMENorth Dakota: 1 filingND1Illinois: 1 filingIL1Minnesota: 0 filingsMNNew Jersey: 0 filingsNJNew York: 0 filingsNYMassachusetts: 0 filingsMAWashington: 1 filingWA1Oregon: 1 filingOR1Vermont: 0 filingsVTCalifornia: 0 filingsCANevada: 1 filingNV1Hawaii: 2 filingsHI2
FewerMore filingsNone

Often filed with

Standard-style form numbers that appear in the same filings most often.

  • WC 00 04 21Catastrophe (Other Than Certified Acts of Terrorism) Premium Endorsement136 filings
  • WC 00 04 22Terrorism Risk Insurance Program Reauthorization Act Disclosure Endorsement136 filings
  • WC 00 03 08Partners, Officers and Others Exclusion Endorsement135 filings
  • WC 00 04 03Experience Rating Modification Factor Endorsement135 filings
  • WC 00 04 14Notification of Change in Ownership Endorsement135 filings
  • WC 00 00 00Workers Compensation and Employers Liability Insurance Policy134 filings
  • WC 00 04 12Contingent Experience Rating Modification Factor Endorsement134 filings
  • WC 00 03 13Waiver of Our Right to Recover From Others Endorsement133 filings
  • WC 00 03 10Sole Proprietors, Partners, Officers and Others Coverage Endorsement132 filings
  • WC 00 04 06Premium Discount Endorsement130 filings

Recent filings

Latest filings that include this form number. Filed copies open in FilingFocus.

SubmittedCompanyStateEditionsTracking number
Nov 2, 2026Illinois Casualty CompanyOROriginalILCC-135079829
Sep 16, 2026ZNAT Insurance CompanyCTOriginalZICO-135090521
Aug 18, 2026RLI Insurance CompanyCOOriginalRLSC-135057018
Jul 1, 2026Acuity, A Mutual Insurance CompanyCOOriginalACUT-134982793
Jun 30, 2026American Casualty Company of Reading, Pennsylvaniaand 5 moreCOOriginalCNAB-135003197
Jun 30, 2026Crestbrook Insurance Companyand 1 moreCOOriginalNWPP-135003409
Jun 30, 2026National Casualty CompanyCOOriginalNWPP-135004216
Jun 24, 2026Atlantic Specialty Insurance Companyand 2 moreCOOriginalBEAC-134978198
Jun 23, 2026Allmerica Financial Alliance Insurance Companyand 5 moreCOOriginalHNVX-134968029
Jun 12, 2026All America Insurance Companyand 1 moreCOOriginalCEMC-134982050
Jun 11, 2026Nationwide Assurance Companyand 3 moreCOOriginalNWPP-G134983730
Jun 11, 2026AMCO Insurance Companyand 1 moreCOOriginalNWPP-G134983819

View all 141 filings

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