The $487 Medicare Surprise Retirees With Large Social Security Checks Don’t See Coming

As a general rule, most seniors would rather have large Social Security checks in retirement than smaller ones. And there are steps you can take to score larger Social Security benefits.

Boosting your wages during your working years is a great way to get more Social Security, as is delaying your claim past full retirement age. Each year you wait, until you turn 70, gives your monthly benefits a permanent 8% increase.

But larger Social Security checks, especially when combined with other retirement income streams, could have a surprisingly unfavorable consequence. And it’s important to know what to look out for in the context of Medicare.

Bigger Social Security checks could spell trouble for Medicare enrollees

Many retirees find that healthcare is one of their biggest expenses, if not the biggest. And Medicare can play a huge role in that.

There’s a basic cost to having Medicare coverage. Though Part A, which covers hospital care, is free for most enrollees, Part B, which covers outpatient care, comes with a monthly premium.

Each year, the Centers for Medicare & Medicaid Services releases a standard monthly premium for Part B. In 2025, it was $185. This year, it rose to $202.90.

The problem is that not all Medicare enrollees pay the same amount of money for Part B. Higher earners can be assessed surcharges known as income-related monthly adjustment amounts, or IRMAAs.

The amount IRMAAs cost can change from year to year, as can the income thresholds that determine whether they apply. But this year, the highest IRMAA threshold adds $487 per month to the cost of Part B.

Now IRMAAs are based on income from two years prior. So seniors facing IRMAAs in 2026 had higher incomes in 2024.

But you should recognize that if you have large Social Security checks combined with other substantial retirement income streams, you may be looking at IRMAAs. And while your Medicare premium costs may not rise immediately, they could rise a couple of years following a high-income year.

Know what to plan for

The good news is that only about 8% of Medicare Part B enrollees are stuck paying IRMAAs. And within that 8%, there are different IRMAA tiers.

The lowest IRMAA tier, for example, adds $81.20 a month to the cost of Part B this year. That’s not wonderful, but it’s not nearly as bad as a $487 increase.

Also, to be fair, that maximum $487 increase only applies to retirees with very high incomes — specifically, single tax-filers with a modified adjusted gross income (MAGI) equal to or greater than $500,000 and joint filers with a MAGI of $750,000 or higher.

Your Social Security checks alone aren’t going to push you into these categories, no matter how large they are. But big Social Security checks combined with a lot of other income might.

For example, if you’re single with a large traditional IRA balance, you may have to withdraw $475,000 in RMDs. If you also collect $5,000 a month in Social Security, your total income could be high enough to face the largest possible Part B IRMAA.

This isn’t to say that you shouldn’t try to get as much out of Social Security as possible. Rather, it’s to know that IRMAAs exist and plan for them accordingly.

That could mean working with a financial advisor or tax professional on ways to reduce your taxable income, such as taking losses in investment accounts strategically and doing Roth conversions ahead of retirement. Proper planning could help you avoid an IRMAA shock, even if your income is generous enough in theory to absorb it.

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