---
title: "NCCI Experience Modification Calculator"
method: POST
path: "/v1/tools/compute_experience_mod"
tags: ["TODO_TAGS_REVIEW", "TODO_AP2_EXPORT_REVIEW"]
---

# NCCI Experience Modification Calculator

`POST /v1/tools/compute_experience_mod`

## Request

- Base URL: `https://ainumbers.co`
- URL: `https://ainumbers.co/v1/tools/compute_experience_mod`
- Auth: none declared

Workers'-compensation experience rating modification (NCCI Experience Rating Plan Manual published national formula): per-claim primary/excess loss split at the state split point, then Mod = (Ap + W×Ae + (1-W)×Ee + B) / (Ep + B). Split point, expected losses, expected primary losses, weighting value, and ballast value are licensed NCCI/state rating-bureau table values supplied by the caller from their own experience rating worksheet -- this node never vendors or reproduces those tables, only the published split-and-mod formula.

**Tool URL:** https://ainumbers.co/chaingraph/art-346-compute-experience-mod.html

## Request body

- object
  - `ballast_value` number
  - `claims` unknown[], required
    - unknown
  - `expected_losses` number
  - `expected_primary_losses` number
  - `split_point` number
  - `weighting_value` number

## Response `200`

Successful tool execution result

- object
  - `actual_excess_losses` integer
  - `actual_primary_losses` integer
  - `actual_total_losses` integer
  - `ballast_value` integer
  - `claim_count` integer
  - `expected_excess_losses` integer
  - `expected_losses` integer
  - `expected_primary_losses` integer
  - `mod` number
  - `note` string
  - `rating_class` string
  - `regulatory_basis` string
  - `split_point` integer
  - `weighting_value` number

---

[API](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite.md) · [All operations](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/llms.txt) · [OpenAPI document](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/revisions/b462e4f5bb28?raw)