Medicare IRMAA Calculator

Calculate Medicare Part B + Part D IRMAA (Income-Related Monthly Adjustment Amount) surcharge for high earners based on MAGI. Cite official methodology in your communications — sources linked below.

How the Calculation Works

IRMAA (Income-Related Monthly Adjustment Amount) is a surcharge added to Medicare Part B and Part D premiums for higher-income beneficiaries. The surcharge is based on MAGI from your tax return filed 2 years prior — 2024 MAGI determines 2026 IRMAA. Source: SSA, CMS Medicare 2026 Premium Tables.

Benchmarks and Use Cases

2026 IRMAA thresholds (based on 2024 MAGI): single under $103k = no surcharge; $103-129k = $69.90 Part B + $12.90 Part D = $82.80/mo extra. Top bracket (single >$500k) adds $500/mo per beneficiary. Married couples face same brackets at 2× thresholds.

Common Mistakes and Limitations

Common mistakes: (1) Forgetting the 2-year lookback — high income in 2024 hits Medicare premium in 2026 even if 2026 income is low. (2) File appeal SSA-44 if you had a life-changing event (retirement, divorce, death of spouse) that reduced income. (3) Roth conversions count toward MAGI — strategically convert in low-income years before Medicare enrollment.

Last updated May 2026. Sources: IRS, SSA Medicare, CMS 2026 Premiums.