Healthcare

Medicare IRMAA Part B & Part D surcharges

Computes the Medicare income-related monthly adjustment amount (IRMAA) — the Part B and Part D surcharges high-income beneficiaries pay on top of the standard premiums — from the benefit year, filing status, and MAGI. IRMAA uses MAGI from two years before the benefit year (a cliff: $1 over a threshold triggers the full surcharge). Returns the tier, monthly and annual surcharge, and the headroom to the next tier (which drives Roth / withdrawal decisions). Year-keyed SSA/CMS tables. Deterministic.

post/v1/medicare/irmaa

Request

  • Base URL: https://api.numeratica.com
  • URL: https://api.numeratica.com/v1/medicare/irmaa
  • Auth: one of:
    • HTTP bearer
    • API key in header X-API-Key

Request body

irmaa_yearinteger required

Benefit year. Supported: 2025, 2026. Uses MAGI from two years prior.

filing_status'single' | 'mfj' | 'mfs' | 'hoh' required

hoh uses the individual thresholds.

maginumber required

Modified adjusted gross income (from the 2-year-lookback year).

Example request

{
  "irmaa_year": 2026,
  "magi": 280000
}

Response

IRMAA result

result_idstring
engine_versionstring
disclaimerstring

Example response

{
  "result_id": "irmaa_1a2b3c4d5e6f7a8b",
  "engine_version": "irmaa-1.0.0",
  "inputs": {
    "irmaa_year": 2026,
    "magi": 280000
  },
  "result": {
    "tier": 1
  }
}

Changes

No recorded changes to this operation across all 1 revision of this API.