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A retiree with $220,000 in combined income from Social Security, pension payments, and investment returns will pay $3,409 for Medicare Part B in 2026, while someone earning $215,000 pays just $2,435. That $974 difference comes from crossing a single income threshold by $5,000. The surcharge is called the Income-Related Monthly Adjustment Amount, and it catches more retirees every year as inflation pushes income higher while the brackets adjust more slowly.
How the Two-Year Lookback Creates Surprises
IRMAA operates on a two-year delay. Your 2026 Medicare premiums are determined by your 2024 Modified Adjusted Gross Income, which the Social Security Administration pulls directly from IRS records. A one-time event two years ago, like a large IRA withdrawal, a home sale, or a Roth conversion, can trigger higher premiums today even if your current income has dropped back down.
The standard 2026 Medicare Part B premium is $202.90 per month, but once income crosses $109,000 for single filers, surcharges begin immediately and climb steeply. The first bracket alone adds $81.20 per month per person — a jump that illustrates how crossing a single income line can cost a household nearly $2,000 more per year. For the highest earners, premiums reach $689.90 per month for Part B alone. Medicare Part D layers on additional surcharges, meaning the combined impact can be substantial for retirees who do not anticipate these thresholds.
Where Asset Income Pushes Retirees Over the Line
The problem for many retirees is not salary. Bond interest, dividend payments, and capital gains distributions all count toward the MAGI calculation that determines IRMAA liability. Income from assets reached $4.2 trillion in Q3 2025, up 2.3% from the same period in 2024. A couple pulling $60,000 from Social Security, $80,000 from a pension, and $85,000 from taxable investment accounts lands at $225,000 in MAGI, putting each spouse at $284.10 per month instead of $202.90. That costs the household an extra $1,948 per year.
The brackets adjust annually for inflation, but not always at the pace of actual income growth. Inflation ran 2.16% year-over-year as of January 2026, while per capita disposable income grew 5.3% over the same period. That gap means more retirees are crossing into IRMAA territory even when their standard of living has not changed.
What Retirees Should Focus On
Financial planners often note that the two-year lookback means large taxable events like Roth conversions, stock sales, or retirement account withdrawals can affect IRMAA liability two years later. Strategies such as spreading IRA withdrawals across multiple years, harvesting capital losses, or using Roth withdrawals have been cited as ways some retirees manage MAGI levels. Readers should consult a tax professional to understand how these approaches may apply to their situation.
The Social Security Administration allows appeals for life-changing events such as retirement, divorce, or loss of a spouse. If your income dropped significantly between the lookback year and today, you can request a redetermination using Form SSA-44. Routine fluctuations do not qualify. For couples, married filing separately brackets start surcharges at $109,000 rather than $218,000, which in many cases results in higher surcharges than filing jointly.