Coverage description
A National Council on Compensation Insurance (NCCI) standard form. It extends the policy to work subject to the Defense Base Act, described in its schedule or on the Information Page, by treating the work location as an Item 3.A state and adding the Act to the policy's definition of workers compensation law.
Updated
What the form says
Key clauses from edition A, the latest revision, quoted as filed.
“This endorsement applies only to the work described in the Schedule or described on the Information Page as subject to the Defense Base Act.”
WC 00 01 01 A
Which work the endorsement reaches. Coverage is tied to a description of the work, not to a state. Work under the Act that is not described in the schedule or on the Information Page is outside the endorsement.
“as though the location included in the description of the work were a state named in Item 3.A. of the Information Page.”
WC 00 01 01 A
The work location is treated as a covered state. The location named in the work description stands in for an Item 3.A state, so Parts One and Two apply there even when the location is not a state.
“and the Defense Base Act (42 USC Sections 1651–1654)”
WC 00 01 01 A
The Act becomes part of the workers compensation law. General Section C is rewritten to include the Act, so Part One pays the benefits it requires. Other federal compensation and occupational disease laws stay outside the definition.
“exclusion 8, does not apply to work subject to the Defense Base Act.”
WC 00 01 01 A
Employers liability is restored for that work. Part Two exclusion 8 of the policy removes employers liability for work under federal compensation laws. This sentence switches that exclusion off for work under the Defense Base Act.
How the form has changed
Filed copies carry revision A (Ed. 4-92), and no copy of the earlier NCCI edition with stored text has been filed, so there is nothing to compare.
Editions
Revision letters as filed, newest first. Filing counts include every state submission that lists the edition.
| Edition | Filings | Companies | States | Filed | Document |
|---|---|---|---|---|---|
| ALatest | 109 | 73 | 13 | Jan 2022 to Nov 2026 | View PDF |
What the filings show
- Edition in use: in the past 12 months, 35 companies filed edition A.
- WC 00 01 04 (Federal Employers' Liability Act Coverage Endorsement) is filed alongside it most often, in 106 of the same filings (97%).
Filed under
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 01 01, out of 26 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 | A | Jun 4, 2026 |
| Nationwide Corporation Group3 group companies filed it, led by Crestbrook Insurance Company and National Casualty Company | 10 | 1 | A | Jun 30, 2026 |
| AXA Insurance Group5 group companies filed it, led by Greenwich Insurance Company and XL Insurance America, Inc. | 6 | 2 | A | Jun 23, 2026 |
| Tokio Marine Holdings Incorporated Group2 group companies filed it, led by Safety First Insurance Company and Safety National Casualty Corporation | 6 | 2 | A | May 14, 2025 |
| Intact Financial Group3 group companies filed it, led by Atlantic Specialty Insurance Company and OBI America Insurance Company | 5 | 1 | A | Jun 24, 2026 |
| RLI Insurance GroupRLI Insurance Company | 5 | 1 | A | 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 | A | Jun 15, 2026 |
| State Farm GroupState Farm Fire and Casualty Company | 5 | 1 | A | May 4, 2026 |
| THE Hanover Insurance Group6 group companies filed it, led by Allmerica Financial Alliance Insurance Company and Allmerica Financial Benefit Insurance Company | 5 | 1 | A | Jun 23, 2026 |
| WR Berkley Corporation Group8 group companies filed it, led by Intrepid Casualty Company and Intrepid Insurance Company | 5 | 3 | A | Sep 23, 2024 |
How the largest insurers handle WC 00 01 01
Groups among the largest workers compensation insurers that filed WC 00 01 01 or their own version in the past five years.
- Travelers GroupFiles its own version: XC 99 0004 (00) Defense Base Act Coverage Endorsement (40 states)
- Amtrust Financial Services GroupUses WC 00 01 01 in 1 filing
States
Number of filings that include WC 00 01 01 in each state, Nov 2021 to Nov 2026. Darker states have more filings.
Often filed with
Standard-style form numbers that appear in the same filings most often.
- WC 00 01 04Federal Employers' Liability Act Coverage Endorsement106 filings
- WC 00 01 08Nonappropriated Fund Instrumentalities Act Coverage Endorsement105 filings
- WC 00 01 06Longshoremen's and Harbor Workers' Compensation Act Coverage Endorsement103 filings
- WC 00 01 09Outer Continental Shelf Lands Act Coverage Endorsement98 filings
- WC 00 03 01Alternate Employer Endorsement98 filings
- WC 00 03 05Joint Venture as Insured Endorsement98 filings
- WC 00 00 00Workers Compensation and Employers Liability Insurance Policy97 filings
- WC 00 03 04Insurance Company as Insured Endorsement97 filings
- WC 00 03 13Waiver of Our Right to Recover From Others Endorsement97 filings
- WC 00 01 11Migrant and Seasonal Agricultural Worker Protection Act Coverage96 filings
Recent filings
Latest filings that include this form number. Filed copies open in FilingFocus.
| Submitted | Company | State | Editions | Tracking number |
|---|---|---|---|---|
| Nov 2, 2026 | AmFed Advantage Insurance Companyand 3 more | WA | A | GREY-135137891 |
| Oct 2, 2026 | AmFed Advantage Insurance Companyand 3 more | CA | A | GREY-135104146 |
| Sep 25, 2026 | AmFed Advantage Insurance Companyand 3 more | MI | A | GREY-135103500 |
| Sep 16, 2026 | ZNAT Insurance Company | CT | A | ZICO-135090521 |
| Aug 18, 2026 | RLI Insurance Company | CO | A | RLSC-135057018 |
| Jun 30, 2026 | Crestbrook Insurance Companyand 1 more | CO | A | NWPP-135003409 |
| Jun 30, 2026 | National Casualty Company | CO | A | NWPP-135004216 |
| Jun 24, 2026 | Atlantic Specialty Insurance Companyand 2 more | CO | A | BEAC-134978198 |
| Jun 23, 2026 | Allmerica Financial Alliance Insurance Companyand 5 more | CO | A | HNVX-134968029 |
| Jun 23, 2026 | AXA XL Insurance Company Americasand 3 more | CO | A | XLAM-134996276 |
| Jun 15, 2026 | Sompo America Fire and Marine Insurance Companyand 1 more | CO | A | SMPJ-134970923 |
| Jun 12, 2026 | All America Insurance Companyand 1 more | CO | A | 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