---
title: "ACA Affordability Safe-Harbor Calculator"
method: POST
path: "/v1/tools/compute_aca_affordability_safe_harbor"
tags: ["TODO_TAGS_REVIEW"]
---

# ACA Affordability Safe-Harbor Calculator

`POST /v1/tools/compute_aca_affordability_safe_harbor`

## Request

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

Compute the ACA employer-mandate affordability percentage under each of the three IRC 4980H(a)(1)(B) safe harbors (W-2 wages, rate-of-pay, federal poverty line) against a supplied lowest-cost self-only monthly premium, using the version-pinned 2026 affordability threshold (9.96%, IRS Rev. Proc. 2025-25). Returns per-harbor affordability verdicts and which harbor(s) the offer satisfies. Root node of the aca-226j-response-composer chain. Not tax or legal advice -- calculation evidence only. Zero network, zero PII.

**Tool URL:** https://ainumbers.co/chaingraph/art-298-aca-affordability-safe-harbor.html
**AP2/Policy Mandate export:** yes

## Request body

- object
  - `fpl_mainland_annual` unknown, required
  - `hourly_rate` unknown, required
  - `lowest_cost_self_only_monthly_premium` unknown, required
  - `tax_year` unknown, required
  - `w2_box1_wages_annual` unknown, required

## Response `200`

Successful tool execution result

- object
  - `affordability_pct` number
  - `error` string
  - `harbors` object
    - `fpl` object
      - `affordable` boolean
      - `computed` boolean
      - `monthly_max_employee_contribution` number
    - `rate_of_pay` object
      - `affordable` string
      - `computed` boolean
      - `monthly_max_employee_contribution` string
    - `w2` object
      - `affordable` boolean
      - `computed` boolean
      - `monthly_max_employee_contribution` number
  - `harbors_satisfied` string[]
  - `lowest_cost_self_only_monthly_premium` integer
  - `satisfies_any_harbor` boolean
  - `tax_year` string

---

[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)