How Your 2025 Tax Return Sets Your 2027 Medicare Premium: The Income Surcharge Explained

The bottom line: your Medicare bill has a two-year memory

Here is a quick test. Find your 2025 tax return and look at one line: adjusted gross income. If you are on Medicare in 2027, or will be, that number helps decide what you pay for Part B and Part D coverage for the whole year.

Most people treat that line as a tax figure. It is also a premium quote. Medicare charges higher-income enrollees an extra amount on top of the standard premium, and it sets that amount using your tax return from two years earlier. The official name is the income-related monthly adjustment amount. In plain English, it is a surcharge that rises in steps as your income crosses certain brackets.

That leaves two kinds of retirees. Premium takers find out about the surcharge when the notice arrives. Premium planners see it coming and shape their income before it lands on a return. The second group usually has more choices, and choices are what this article is about.

2025: the income year Medicare looks at

Medicare starts with your adjusted gross income, the figure on your return after certain adjustments but before the standard or itemized deduction. Wages, business profit, capital gains, Roth conversions and traditional IRA withdrawals all count toward it.

Then it adds back tax-exempt interest. Municipal bond interest is not taxed on your federal return, but Medicare includes it anyway. Many people are surprised to learn that their tax-free income still raises their premium.

Itemized deductions do not help here either. A large charitable gift lowers your taxable income, but it does not lower adjusted gross income, so it does not lower the figure Medicare uses.

The real risk is the single big year. Picture a physician who sells her share of the building her practice operates from and reports a $600,000 gain on top of her usual income. That one sale can push her into a higher surcharge bracket for a full year of premiums, even if her income drops right back down the next year. Social Security publishes the bracket thresholds each year, and we check them against your numbers rather than guessing.

2026: you file, and you are already earning the next year

When you file your 2025 return in 2026, it becomes the record Social Security uses. Late in 2026, Social Security sets 2027 premiums. If your 2025 income is above the surcharge thresholds, you receive a notice explaining the added amount for Part B and Part D for all of 2027.

Married couples should pay close attention. Each spouse on Medicare is assessed separately, but the assessment uses your joint income. One big year on a joint return can raise two premiums, not one.

Meanwhile, the income you earn during 2026 will set your 2028 premiums. So planning in 2026 covers two years at once: the bill already in motion and the next one you can still shape.

2027: you pay, or you request a review

If your income has dropped because of a qualifying life-changing event, you can ask Social Security to reconsider using more recent income. Qualifying events include stopping work, reducing work, marriage, divorce, the death of a spouse, and the loss of income-producing property or a pension. The request is made on a form Social Security calls the SSA-44.

Be honest with yourself about what qualifies. A one-time gain from selling assets typically does not count as a life-changing event. Selling a rental property or part of a business is a choice, and Medicare generally treats it that way.

This is a legitimate process, but documentation matters. You will need proof of the event and a reasonable estimate of your new income, such as a letter confirming your retirement date or records showing reduced hours. When the facts support a request, we help clients prepare it so the case is clear on the first review.

How to plan a big income year before it lands

The best time to manage the surcharge is before the income shows up. Because of the two-year lookback, income at age 63 sets premiums at 65. That makes your early sixties a planning window, not just a countdown.

Spread large events where you can. Roth conversions can often be split across several years, or finished before the lookback years begin. A business or property sale may be structured as an installment sale, which spreads the gain over the years you receive payments. Each approach has trade-offs, and we model them side by side.

Use contributions that lower adjusted gross income. If you are still working, a pre-tax 401(k) deferral of the full $24,500 employee limit lowers the income Medicare sees by $24,500. At a 24% federal tax rate, it also lowers federal tax by about $5,880. Catch-up contributions can add more, though some higher earners must make catch-ups as Roth, which does not lower current income. We confirm which rules apply to you.

Finally, sometimes the right answer is to accept the surcharge. A Roth conversion that costs a year of higher premiums may still come out ahead over a long retirement. The goal is not to dodge the surcharge at all costs. It is to know the price before you decide.

Plan the premium with the decision

Profit is what you sell. Wealth is what you keep. A practice sale, a property sale or a large conversion can be the right move, and its Medicare cost is part of the math.

If a big income year is coming, such as an exit, a conversion or a property sale, the time to plan its Medicare cost is before it lands on a return. After that, the number is already set.

Key takeaways

• Medicare sets Part B and Part D surcharges using your tax return from two years earlier, so 2025 income drives 2027 premiums.
• Tax-exempt interest is added back, and itemized deductions do not reduce the income Medicare uses.
• Married couples are each assessed on joint income, so one big year can raise two premiums.
• A one-time asset sale typically does not qualify for reconsideration, but stopping or reducing work may, with documentation.
• Income at age 63 sets premiums at 65, which makes your early sixties the window to spread conversions and sales.

If you have an exit, a property sale or a Roth conversion on the horizon, let's map its tax and Medicare cost together before it lands on a return. Book a planning conversation with Eiduk Tax & Wealth and we will show you the numbers side by side. Pay Less. Keep More. Build Wealth.