Retirees who earned more than roughly $112,000 in modified adjusted gross income during 2025 are on track to pay a Medicare Part B surcharge in 2027, with the highest earners facing a projected monthly premium above $712. The numbers come from the 2026 Medicare Trustees Report, which projects a standard Part B premium of $209.50 per month and a top-tier income-related monthly adjustment amount, known as IRMAA, of $502.60. Combined, those two figures total $712.10 per month for beneficiaries in the top income bracket, a sharp increase from the finalized 2026 standard premium of $202.90.
The two-year lookback that turns 2025 earnings into 2027 bills
The Social Security Administration determines IRMAA using the most recent tax return data supplied by the IRS, which in practice creates a two-year lag. That means income reported on a 2025 federal return will set the surcharge a retiree pays starting in January 2027. For single filers, the projected threshold for 2027 coverage sits at roughly $112,000, while joint filers face a corresponding bracket near $218,000. Anyone below those lines pays only the standard premium. Everyone above enters a tiered system in which beneficiaries cover 35, 50, 65, 80, or 85 percent of total Part B costs, depending on how far their income exceeds the cutoff.
The gap between the finalized 2026 standard premium of $202.90 and the projected 2027 standard premium of $209.50 amounts to a 3.3 percent increase on the base rate alone. But for higher earners, the surcharge amplifies the jump. A retiree in the second-lowest IRMAA tier would see a smaller add-on, while those at the top face the full $502.60 monthly surcharge on top of the standard premium. That layered structure means the percentage increase from 2026 to 2027 grows steeper at each rung of the income ladder.
Trustees Report projections and what the data actually shows
The core projections appear in the 2026 report prepared by the CMS Office of the Actuary. Table V.E2 in that document lists the $209.50 standard monthly Part B premium for 2027 under baseline assumptions. Table V.E3 details the IRMAA surcharges by tier, with the top-tier monthly add-on at $502.60. Together, those tables underpin the projected $712.10 monthly bill for the highest-income beneficiaries in 2027.
These figures are projections, not finalized rates. Medicare premiums are set each year based on updated spending data, enrollment trends, and statutory formulas. CMS will announce official 2027 premiums and IRMAA brackets later, typically in the fall before the coverage year begins, and those final numbers can differ from the actuarial baseline. Still, the Trustees’ estimates offer the best available early look at how much retirees may pay and how the burden is likely to be distributed across income levels.
The income brackets themselves are indexed to inflation using the Consumer Price Index for All Urban Consumers, or CPI-U, published by the Bureau of Labor Statistics. Because monthly CPI-U readings for the full measurement window needed to lock in 2027 brackets have not all been released, the $112,000 single-filer threshold remains an estimate. The 2025 report offered earlier projections for the same period, and comparing the two editions shows how year-over-year revisions in inflation assumptions can nudge both premiums and income thresholds higher or lower. Small changes in the CPI-U path compound over time, which is why the Trustees revisit and update these estimates annually.
For retirees trying to plan ahead, the most important takeaway is not the exact dollar figure but the structure: a standard premium that rises gradually with overall Part B costs, and a set of IRMAA tiers that shift upward over time with inflation but still concentrate a much larger share of program financing on higher-income enrollees. Those basic mechanics are unlikely to change between the projection and the final announcement, even if the precise thresholds move slightly.
How IRMAA surcharges are calculated and appealed
IRMAA is triggered when a beneficiary’s modified adjusted gross income from two years prior exceeds the applicable threshold for their filing status. The Social Security Administration receives that income information directly from the IRS and applies the statutory percentage for the appropriate tier to determine the monthly surcharge. Beneficiaries then see the combined amount-standard premium plus IRMAA-deducted from their Social Security benefits or billed directly if they are not yet collecting retirement payments.
Because the system relies on a two-year-old tax return, it can misrepresent a retiree’s current financial situation, especially after major life events such as retirement, divorce, or the death of a spouse. In those cases, individuals can request a new determination and ask SSA to use more recent income information. The agency outlines these rules and the current year’s brackets on its official Medicare premiums page, which also explains how IRMAA applies to both Part B and Part D coverage.
Looking ahead to 2027, retirees whose 2025 income hovers near the projected thresholds may want to pay close attention to how additional taxable income-such as large capital gains, Roth conversions, or one-time distributions-could push them into a higher IRMAA tier. While the Trustees Report projections are not a guarantee, they provide a useful planning benchmark, especially for those seeking to avoid unexpected premium shocks two years down the line.
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