Medicare’s Income-Related Monthly Adjustment Amount (IRMAA) for 2026 is determined by the income you reported on your 2024 federal tax return, under the standard two-year lookback. The Centers for Medicare and Medicaid Services (CMS) released the official 2026 brackets and surcharges on November 14, 2025. A one-time income event such as a property sale or a Roth conversion can bump a household into a higher tier for a full calendar year before the surcharge drops back.
IRMAA touches a minority of beneficiaries. CMS estimates roughly 8% of people with Medicare Part B pay any surcharge at all, and a similar share pay the Part D adjustment. If your modified adjusted gross income (MAGI) sits comfortably below the first threshold, none of this applies. For everyone else, the 2026 brackets determine exactly where the cliffs land and what crossing one by even a single dollar costs over the next 12 months.
The 2026 Part B Income Brackets
MAGI for IRMAA purposes equals adjusted gross income (Form 1040, line 11) plus tax-exempt interest (line 2a). Municipal bond income that feels tax-free still counts toward MAGI, which is the most common reason a household near a threshold misjudges its bracket and faces an unexpected surcharge.
The 2026 Part B figures below come directly from CMS and use your 2024 return as the income reference. The standard monthly Part B premium in 2026 is $202.90, up from $185.00 in 2025, with IRMAA surcharges layered on top for higher-income beneficiaries.
| Single MAGI (2024) | Joint MAGI (2024) | Monthly Part B surcharge (per person) | Total monthly Part B premium (per person) |
|---|---|---|---|
| ≤ $109,000 | ≤ $218,000 | $0.00 | $202.90 |
| $109,001 to $137,000 | $218,001 to $274,000 | $81.20 | $284.10 |
| $137,001 to $171,000 | $274,001 to $342,000 | $202.90 | $405.80 |
| $171,001 to $205,000 | $342,001 to $410,000 | $324.60 | $527.50 |
| $205,001 to under $500,000 | $410,001 to under $750,000 | $446.30 | $649.20 |
| ≥ $500,000 | ≥ $750,000 | $487.00 | $689.90 |
The first single-filer threshold rose from $106,000 to $109,000 between 2025 and 2026, a 2.83% increase, and the joint threshold sits at exactly twice that. The remaining breakpoints shifted by similar proportions. The top tier at $500,000 single and $750,000 joint carries no current inflation indexing, though current law makes it eligible for annual indexing beginning in 2028.
The 2026 Part D Surcharges
Part D uses the same five income tiers as Part B but adds a separate fixed monthly amount on top of whatever your drug plan charges. The per-person monthly surcharges for 2026 run $14.50 at Tier 1, $37.50 at Tier 2, $60.40 at Tier 3, $83.30 at Tier 4, and $91.00 at the top tier. A household in Tier 1 therefore pays an extra $14.50 for Part D on top of the $81.20 Part B add-on, for a combined monthly IRMAA burden of $95.70 per enrolled person.
Medicare deducts the Part D adjustment directly from your Social Security check when that benefit is large enough to cover it. If it is not, or if you have deferred Social Security, CMS bills the surcharge separately. Either way, the charge goes to Medicare rather than to your plan, and it is owed regardless of who pays the underlying Part D premium on your behalf.
The Cliff: What One Dollar Over Costs
IRMAA operates as a hard cliff at each threshold, not a gradual phase-in. A single filer with 2024 MAGI of exactly $109,000 pays the standard $202.90 Part B premium in 2026. A single filer at $109,001 pays $284.10, an extra $81.20 per month for the full year. Adding the $14.50 Part D surcharge, that one dollar of MAGI triggers roughly $1,148 in combined added Medicare costs across 12 months for a single filer, or close to double that for a married couple where both spouses are enrolled in Medicare.
The same logic plays out at every subsequent tier boundary. Moving from Tier 1 to Tier 2 adds another $121.70 per month in Part B alone (the difference between the $202.90 and $81.20 surcharges). For a retiree at the top tier, the total Part B premium reaches $689.90 per month, more than triple the standard amount, and the annual surcharge burden across both Part B and Part D can exceed $6,900 per person.
The Two-Year Lookback
Your 2024 return set your 2026 surcharge. Your 2025 income will set your 2027 premiums, and your 2026 income, the year you are currently living through, will set your 2028 premiums. Closed years are locked: a Roth conversion completed in 2024 already sits inside the 2026 bracket calculation with no way to unwind it for IRMAA purposes.
That lag is also why one-time events produce most surprise surcharges. A home sale, a Required Minimum Distribution in the year you turn 73, a severance payment, or a large Roth conversion can push a household one tier higher, or several, for a single year, then drop it back the next. The 2027 and 2028 surcharges are still shapeable by income decisions made today.
The Survivor Trap
The joint thresholds sit at exactly twice the single thresholds. When one spouse dies and the survivor files single in the following tax year, the same household income that rested comfortably under the $218,000 joint threshold can easily clear the $109,000 single threshold and climb several tiers. The income did not change; the filing status did, and the bracket moved with it.
A related and often overlooked hazard applies to couples who file separately. Spouses who lived together at any point during the tax year and used the married-filing-separately (MFS) status face a compressed, three-tier bracket structure rather than the standard five tiers. One penny above $109,000 MAGI immediately triggers the Tier 4 equivalent surcharge, meaning an MFS filer at $109,001 in 2024 MAGI owes $529.60 per month in combined Part B and Part D IRMAA for 2026, compared to $95.70 per month for a single filer with identical income. That is more than five times the surcharge for the same income level, purely as a result of filing status.
What SSA-44 Does and Does Not Do
The Social Security Administration’s Form SSA-44 lets you request a recalculation when income drops because of a qualifying life-changing event. The list of qualifying events includes marriage, divorce or annulment, death of a spouse, work stoppage, work reduction, loss of income-producing property, loss of pension income, and an employer settlement. When approved, SSA uses a more recent year’s income to recalculate the surcharge, potentially eliminating or significantly reducing it.
SSA-44 cannot reverse a voluntary income event. A Roth conversion, a home sale, or an RMD that pushed MAGI over a threshold does not qualify, however large the resulting surcharge. The form is limited to situations where income fell due to a specific life change, and supporting documentation (a retirement letter, death certificate, divorce decree, or employer notice) is required at the time of filing.
Practical Considerations
- Add Form 1040 line 11 and line 2a from your 2024 return, then find your household in the table above. That sum is your 2026 MAGI for IRMAA purposes and determines which surcharge tier applies.
- If your household sits within roughly $20,000 of any 2026 bracket edge, model your 2025 and 2026 income before year-end. Sizing a planned Roth conversion or distribution to land just under the next cliff can preserve a lower 2027 or 2028 premium tier, since those years are still in play.
- If you are a surviving spouse filing single for the first time, your income runs against the single column, not the joint one. That transition year is when survivor IRMAA surprises most commonly appear.
- Couples who file separately and lived together during the tax year face a sharply compressed bracket structure. The same income that triggers a modest Tier 1 surcharge for a single filer triggers a Tier 4 surcharge under MFS status.
- When a qualifying life-changing event reduces your income, file SSA-44 promptly with supporting documentation rather than waiting for the next annual recalculation. The SSA can substitute a more recent income year, which may eliminate the surcharge entirely.
Editor’s note: This update added the full set of 2026 Part D surcharge amounts across all five tiers ($14.50 through $91.00 per month), noted that the top IRMAA bracket becomes eligible for inflation indexing beginning in 2028, and added a section explaining the married-filing-separately bracket penalty, under which an MFS filer at $109,001 in 2024 MAGI owes $529.60 per month in combined IRMAA surcharges for 2026 versus $95.70 for a single filer with the same income.
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