---
title: "2026 HSA or health-FSA contribution limit and income-tax savings — HSA self/family limits + age-55 catch-up + HDHP deductible/OOP bounds, or the FSA salary-reduction limit + carryover."
method: POST
path: "/v1/retirement/hsa-fsa"
tags: ["Retirement"]
---

# 2026 HSA or health-FSA contribution limit and income-tax savings — HSA self/family limits + age-55 catch-up + HDHP deductible/OOP bounds, or the FSA salary-reduction limit + carryover.

`POST /v1/retirement/hsa-fsa`

## Request

- Base URL: `` (relative, and it does not resolve against the document’s source URL)
- URL: `/v1/retirement/hsa-fsa`
- Auth: none declared

2026 HSA or health-FSA contribution limit and income-tax savings — HSA self/family limits + age-55 catch-up + HDHP deductible/OOP bounds, or the FSA salary-reduction limit + carryover.

Payment: x402 ($0.05 USDC on eip155:8453). Call unpaid to receive an HTTP 402 with requirements, then retry with the PAYMENT-SIGNATURE header. Method: HSA limit = (self $4,400 / family $8,750) + (age≥55 ? $1,000 : 0); FSA limit = $3,400; tax savings = min(contribution, limit) × marginal rate

## Request body

- object
  - `accountType` 'hsa' | 'fsa'
  - `coverage` 'self' | 'family'
  - `age` number
  - `contributionAmount` number
  - `marginalRatePct` number

## Response `200`

Verified result + provenance (formula, sources, reproducible SHA-256 hash).

## Other responses

- `400`: Invalid input (no charge) — body echoes the JSON Schema.
- `402`: Payment required — PAYMENT-REQUIRED header carries the x402 accepts[] quote.

---

[API](https://skmtc.dev/x402toll/apis/tollbooth-verified-calculators-for-ai-agents.md) · [All operations](https://skmtc.dev/x402toll/apis/tollbooth-verified-calculators-for-ai-agents/llms.txt) · [OpenAPI document](https://skmtc.dev/x402toll/apis/tollbooth-verified-calculators-for-ai-agents/revisions/60cb70a3e1a5?raw)