What the calculator adds—and what it deliberately leaves out
The tool first adds 2024 Form 1040 line 11 and line 2a. That is the Medicare IRMAA MAGI definition published by the Social Security Administration. It then applies the selected 2024 filing-status table to the official 2026 amounts. For Part B, the result includes the standard $202.90 monthly premium plus any IRMAA. For Part D, it includes only the IRMAA charged in addition to the premium set by the drug plan.
The result is per enrollee before it becomes a household total
IRMAA is not one surcharge per tax return. Each Medicare beneficiary pays the amount for the bracket. When a jointly filing couple has two Medicare enrollees, the calculator doubles each included per-person amount. If only one spouse is enrolled, choose one. For non-joint returns, run each beneficiary’s return separately.
Exact 2026 income boundaries matter
The first IRMAA tier begins above $109,000 for an individual-table return and above $218,000 for a joint return. The regular individual and joint tables then have higher levels through the top tier beginning at $500,000 and $750,000 respectively. A married-filing-separately beneficiary who lived with a spouse during any part of 2024 uses a compressed special table: above $109,000 and below $391,000 is the fourth IRMAA level, while $391,000 or more is the top level.
The CMS 2026 premium fact sheet publishes the exact brackets, Part B totals, and Part D adjustments. The SSA Medicare premium table explains that 2026 generally uses the 2024 return.
A life-changing event creates a request path, not an automatic lower premium
SSA may make a new determination when income falls because of a qualifying event such as marriage, divorce, a spouse’s death, work stoppage or reduction, loss of income-producing property, loss of pension income, or certain employer settlement payments. The result points affected users to SSA’s current process and Form SSA-44. A one-time high-income event by itself is not automatically a qualifying life-changing event.
If the IRS information is wrong, an amended return exists, SSA used an older return, or the filing status and living arrangement were classified incorrectly, follow the correction or appeal route on the notice. Those situations are not solved by substituting a preferred number into this calculator. Read the 2026 Medicare IRMAA guide before deciding which route fits.
Why a premium notice can differ from this estimate
The result excludes Part D plan premiums, Part B and Part D late-enrollment penalties, Part A premiums, employer or Medicaid assistance, Medicare Savings Programs, Medicare Advantage premium reductions, special Part B immunosuppressive-drug-only coverage, midyear enrollment, and rounding or collection adjustments. SSA can also use the most recent return the IRS provides, sometimes from 2023 rather than 2024.
This calculator provides general educational arithmetic for the published 2026 federal Medicare IRMAA tables. It is not medical, tax, legal, benefits, or financial advice and does not determine eligibility, coverage, appeals, or the amount on an official notice. Verify the tax year, MAGI, filing status, enrollment, plan premium, penalties, assistance, and official SSA determination before budgeting or acting.