Coverage description
A National Council on Compensation Insurance (NCCI) standard form. It changes the retrospective rating plan premium endorsement on the policy through up to three options: adding allocated loss adjustment expense to incurred losses, fixing the basic premium factor without interpolation, and valuing losses on dates you and the insurer agree.
Updated
What the form says
Key clauses from edition A, the latest revision, quoted as filed.
“The retrospective rating plan premium endorsement attached to the policy is changed by the selection of one or more of the options shown below in the Schedule.”
WC 00 05 15 A
How the options attach. This form works only alongside a retrospective rating plan premium endorsement on the same policy. It changes that endorsement, and only the options selected in its schedule apply.
“Incurred losses are changed to include allocated loss adjustment expense in these states:”
WC 00 05 15 A
Adding claim expense to losses. In the states entered, allocated loss adjustment expense counts as part of incurred losses, so those claim expenses feed into the retrospective premium.
“basic premium factor for 100% of the estimated standard premium shall be used without linear interpolation”
WC 00 05 15 A
Fixing the basic premium factor. Every calculation uses the basic premium factor set for 100% of estimated standard premium, instead of interpolating a factor from the actual standard premium as the retrospective rating plan endorsements otherwise provide.
“Each calculation of retrospective rating plan premium will use all loss information we have as of a date agreed to by you and us.”
WC 00 05 15 A
Choosing when losses are valued. Losses are valued on dates you and the insurer agree, in place of the fixed valuation dates in the retrospective rating plan endorsement.
How the form has changed
Revision A (Ed. 01-10) renames the form and the endorsement it changes to retrospective rating plan premium endorsement and says it is added to Part Five; the three options are the same as in the 10-93 original.
Editions
Revision letters as filed, newest first. Filing counts include every state submission that lists the edition.
| Edition | Filings | Companies | States | Filed | Document |
|---|---|---|---|---|---|
| ALatest | 74 | 59 | 8 | Jan 2022 to Aug 2026 | View PDF |
1 other edition date appears in one or two filings each, often carrier-specific versions: Original.
What the filings show
- Edition in use: in the past 12 months, 29 companies filed edition A.
- WC 00 05 03 (Retrospective Rating Plan Premium Endorsement One-Year Plan) is filed alongside it most often, in 76 of the same filings (100%).
Filed under
Data from admitted P&C filings with state insurance departments, submitted Nov 2021 to Aug 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 15, out of 20 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 |
| 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 |
| 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 |
| 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 |
| Arch Insurance Group2 group companies filed it, led by Arch Indemnity Insurance Company and Arch Insurance Company | 4 | 1 | A | Apr 8, 2026 |
| Louisiana Workers Compensation GroupPrescient National Insurance Company | 4 | 1 | A | Jul 2, 2025 |
| American Financial Group4 group companies filed it, led by Great American Alliance Insurance Company and Great American Assurance Company | 3 | 1 | A | Jun 11, 2024 |
| Starr Group2 group companies filed it, led by Starr Indemnity and Liability Company and Starr Specialty Insurance Company | 3 | 1 | A | Jun 25, 2025 |
States
Number of filings that include WC 00 05 15 in each state, Nov 2021 to Aug 2026. Darker states have more filings.
Often filed with
Standard-style form numbers that appear in the same filings most often.
- WC 00 05 03Retrospective Rating Plan Premium Endorsement One-Year Plan76 filings
- WC 00 05 04Retrospective Rating Plan Premium Endorsement Three-Year Plan75 filings
- WC 00 05 05Retrospective Rating Plan Premium Endorsement Wrap-Up Construction Project75 filings
- WC 00 05 11Retrospective Premium Endorsement-- Short Form75 filings
- WC 00 01 04Federal Employers' Liability Act Coverage Endorsement74 filings
- WC 00 01 06Longshoremen's and Harbor Workers' Compensation Act Coverage Endorsement74 filings
- WC 00 01 08Nonappropriated Fund Instrumentalities Act Coverage Endorsement74 filings
- WC 00 01 09Outer Continental Shelf Lands Act Coverage Endorsement74 filings
- WC 00 01 11Migrant and Seasonal Agricultural Worker Protection Act Coverage74 filings
- WC 00 03 04Insurance Company as Insured Endorsement74 filings
Recent filings
Latest filings that include this form number. Filed copies open in FilingFocus.
| Submitted | Company | State | Editions | Tracking number |
|---|---|---|---|---|
| Aug 18, 2026 | RLI Insurance Company | CO | A | RLSC-135057018 |
| Jun 30, 2026 | American Casualty Company of Reading, Pennsylvaniaand 5 more | CO | A | CNAB-135003197 |
| Jun 30, 2026 | Crestbrook Insurance Companyand 1 more | CO | A | NWPP-135003409 |
| 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 4, 2026 | Argonaut-Midwest Insurance Company | CO | A | ARGN-134974739 |
| Jun 4, 2026 | Argonaut Insurance Company | CO | A | ARGN-134974742 |
| Jun 4, 2026 | Rockwood Casualty Insurance Company | CO | A | ARGN-134974764 |
| Apr 8, 2026 | Arch Insurance Company | CO | A | AICO-G134902631 |
| Apr 8, 2026 | Arch Indemnity Insurance Company | CO | A | AICO-G134902710 |
| Jan 8, 2026 | The Cincinnati Casualty Companyand 2 more | NY | A | CNNA-134764673 |
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