Retirees with six-figure incomes are set to pay even more for Medicare in 2027 as the program’s income-related monthly adjustment amounts, known as IRMAA, continue their upward march. The 2025 Medicare Trustees Report projects rising Supplementary Medical Insurance costs that feed directly into higher Part B and Part D premiums, and the surcharge brackets that scale with modified adjusted gross income will follow. For beneficiaries already paying hundreds of dollars a month above the standard premium, the next round of annual adjustments could add several hundred dollars more per year to their total Medicare bill.
Rising SMI costs and what they mean for 2027 IRMAA brackets
The mechanism is straightforward. Under federal law, CMS sets Part B premiums each year based on projected spending for physician services, outpatient care, and other covered benefits. When those costs climb, so does the standard monthly premium, and every IRMAA tier rises in lockstep. The 2025 trustees projections indicate that Part B financing requirements will keep growing into 2027 and beyond, driven by utilization trends and per-beneficiary cost increases across the Supplementary Medical Insurance trust fund.
The IRMAA framework itself is written into 42 U.S.C. Section 1395r, which defines the sliding-scale percentages and threshold amounts that determine how much extra higher earners owe. A parallel provision in Social Security Act Section 1860D-13 applies the same percentage framework to Part D prescription drug coverage. Together, these statutes guarantee that as baseline premiums increase, the dollar gap between the standard rate and the top IRMAA tier widens automatically. Because the surcharges are expressed as percentages of the standard premium, any upward move in the underlying Part B and Part D amounts is amplified for retirees in the upper income brackets.
CMS has already established the standard Part B premium for 2026, and the agency’s official fact sheet lays out the monthly charge and annual deductible that will apply before IRMAA is added. On top of that base, the Social Security Administration uses a set of income tiers to calculate surcharges two years after the tax year in question. The IRMAA tables in SSA guidance show the income ranges and corresponding premium amounts for the 2026 premium year based on 2024 modified adjusted gross income. Those tables illustrate how the add-on amounts increase across five brackets for both Part B and Part D, with each step up in income triggering a higher monthly obligation.
The 2027 tables have not yet been published in SSA’s Program Operations Manual System or the Federal Register, but the trustees’ baseline spending trajectory points clearly upward, meaning the surcharges will almost certainly be recalculated at higher levels when CMS finalizes rates later in 2026. Unless Congress changes the law, retirees whose incomes remain in the same real range could still see higher dollar IRMAA charges simply because the standard premiums they are multiplied against are higher. That dynamic is particularly important for couples with substantial pension income, large taxable investment portfolios or ongoing consulting work that keeps their modified adjusted gross income above the lowest thresholds.
Gaps in the data on IRMAA appeals and investment income
One question that current federal data does not answer is whether more beneficiaries will challenge their IRMAA determinations once the 2027 tables take effect. SSA allows appeals based on specific life-changing events, such as marriage, divorce, the death of a spouse, work stoppage, or a reduction in work hours. A drop in income from the sale or loss of income-producing property also qualifies. As more retirees enter higher brackets because of investment gains, Roth conversions, or required minimum distributions from retirement accounts, the pool of people who cross an IRMAA threshold in one year but fall below it the next is growing.
No publicly available CMS or SSA dataset systematically tracks how many IRMAA assessments are reduced or reversed after beneficiaries file appeals tied to volatile income sources. That leaves policymakers and planners guessing at the scale of the problem for retirees whose modified adjusted gross income is heavily influenced by capital gains, interest and dividends rather than wages. It is also unclear how many near-retirees are making proactive decisions, such as staggering large Roth conversions over several calendar years, specifically to avoid triggering higher Medicare surcharges.
The lack of granular data matters because IRMAA is calculated using tax returns from two years prior, which can be a poor proxy for a retiree’s current financial reality when markets are choppy. A single year with unusually high realized gains can push someone into a much higher bracket for Medicare purposes, even if their ongoing income is far lower. Without better information on how often appeals succeed in these circumstances, it is difficult to evaluate whether the existing life-changing event criteria are adequately protecting beneficiaries from mismatches between past income and present ability to pay.
For now, affluent retirees and their advisers must navigate this uncertainty with careful tax and withdrawal planning. That can mean monitoring projected modified adjusted gross income, timing the recognition of large gains, and understanding how late-career earnings or part-time work might interact with the IRMAA thresholds that will apply two years later. As the 2027 premium year approaches and CMS releases more detailed guidance, the combination of rising SMI costs and limited transparency around appeals will remain a central concern for households trying to manage health-care costs in retirement.
David M. Keller is a finance writer based in Columbus, Ohio, covering personal finance and consumer-focused economic topics. He earned his degree in journalism from Ohio University and began his career reporting on local business and economic trends for a regional media outlet. Since then, he has contributed to a variety of online publications, focusing on clear, practical coverage of topics such as cost of living, debt, and everyday financial decision-making.
