Picture a retired corporate vice president opening her first Medicare billing notice. She expected to pay $202.90 a month for Part B, the same figure she saw on the Centers for Medicare & Medicaid Services website. Instead, the letter from the Social Security Administration says $504.90. The explanation is a single acronym she had never encountered during decades of employer-sponsored coverage: IRMAA, the Income-Related Monthly Adjustment Amount. Her final year of full-time salary, earned two years before she enrolled, pushed her past an income threshold that more than doubled her premium.
She is not alone, and the surcharge is not a glitch. For 2026, the standard Medicare Part B premium is $202.90 per month, with an annual deductible of $283. According to CMS, roughly 93 percent of beneficiaries pay that standard amount. But enrollees whose modified adjusted gross income, or MAGI, crosses specific thresholds owe graduated surcharges that can push the monthly bill as high as $649. The extra cost is automatic, deducted straight from Social Security checks, and rarely understood until the first notice arrives.
How the 2026 surcharge tiers work
IRMAA layers additional charges on top of the base Part B premium in five graduated steps. The Social Security Administration sets each enrollee’s tier by matching their MAGI from the tax return filed two years earlier to a published bracket schedule. For 2026 premiums, SSA is using 2024 tax data.
The SSA’s 2026 premium schedule for individuals filing single returns breaks down as follows:
- MAGI of $106,000 or less: $202.90 per month (standard, no surcharge)
- $106,001 to $133,500: $284.00 per month
- $133,501 to $167,000: $403.70 per month
- $167,001 to $200,000: $504.90 per month
- $200,001 to $500,000: $577.50 per month
- Above $500,000: $649.00 per month
For married couples filing jointly, each threshold roughly doubles. A couple with combined MAGI above $1,000,000 would each owe the $649 maximum, meaning the household could face nearly $15,600 a year in Part B premiums alone, before supplemental or prescription drug coverage.
IRMAA also applies to Medicare Part D. Depending on the income tier, Part D surcharges add between roughly $13 and $85 per month per person. Combined, the Part B and Part D adjustments can push a top-bracket couple’s total Medicare premiums past $17,500 annually.
One detail that surprises many enrollees: IRMAA applies regardless of whether you choose Original Medicare or a Medicare Advantage plan. The surcharge is tied to Part B itself, so switching to an Advantage plan does not eliminate it.
Why the two-year lookback catches people off guard
The timing is the part that blindsides new retirees. Under 20 CFR Section 418.2120, SSA does not look at your current income. It pulls the most recent MAGI the IRS has on file, which almost always reflects earnings from two calendar years before the premium year.
That creates a predictable mismatch. Someone who retires at 63 after earning $250,000 a year will turn 65 and enroll in Medicare. But SSA will still be referencing that $250,000 salary from two years prior. The retiree’s actual income may have dropped to $40,000 in Social Security benefits and modest portfolio withdrawals, yet the premium bill reflects the old paycheck.
One-time income events sharpen the problem. A large severance package, the exercise of stock options, a Roth IRA conversion, or the sale of a rental property can spike MAGI for a single year and ripple into Medicare costs 24 months later. Because the surcharge is applied automatically, with no advance warning beyond the annual SSA determination notice, many retirees do not connect the cause to the cost until the higher amount is already being withheld.
How to appeal or reduce the surcharge
SSA does allow enrollees to request a new determination. If your income has dropped significantly because of a qualifying life-changing event, you can ask the agency to substitute more recent income data for the two-year-old return. The qualifying events are defined narrowly: retirement or a reduction in work hours, marriage, divorce, death of a spouse, loss of income-producing property due to a disaster, or loss of pension income.
The process starts with SSA Form SSA-44, filed along with supporting documentation such as a letter from a former employer confirming retirement or a more recent tax return showing reduced income. SSA reviews the request and issues a revised determination, but the agency does not publish data on approval rates or average processing times. Until a new determination is issued, the higher premium stands.
For people still working and approaching Medicare eligibility, proactive income planning can be more effective than any appeal. Because IRMAA is driven by MAGI, the same strategies that lower taxable income can keep future Medicare surcharges in check. Completing a Roth IRA conversion before age 63 rather than after, spreading the sale of appreciated assets across multiple tax years, or making qualified charitable distributions from an IRA after age 70½ can all help hold MAGI below a surcharge threshold during the years SSA will be watching.
It is also worth noting that IRMAA surcharges may be deductible as a medical expense. Enrollees who itemize on Schedule A can include all Medicare premiums, including IRMAA amounts, in the pool of medical expenses that exceed 7.5 percent of adjusted gross income. For retirees in the higher IRMAA tiers, that deduction can offset part of the sting.
A surcharge that reaches further every year
IRMAA thresholds are adjusted annually for inflation, but the adjustments have not always kept pace with wage growth in higher-income professions. The result is a slow form of bracket creep: earners who would have cleared the surcharge line comfortably a decade ago now land in the first or second IRMAA tier without ever thinking of themselves as wealthy. A dual-income couple where both spouses earn $140,000, solid but hardly extraordinary in many metro areas, can cross the joint filing threshold and face surcharges on both enrollees’ premiums.
Data from the Medicare Payment Advisory Commission (MedPAC) confirms that the share of beneficiaries subject to IRMAA has grown gradually over the past decade, though detailed tier-by-tier breakdowns are limited. What the published brackets make clear is that the gap between the standard premium and the maximum has widened steadily. In 2026, the top-tier enrollee pays more than three times what the standard enrollee pays, a ratio that reflects Medicare’s design as a program requiring higher earners to shoulder a larger share of its financing.
Treating IRMAA as a line item, not a surprise
For retirees already subject to IRMAA, the most practical annual habit is a simple cross-check: compare the income figure on your SSA determination notice to the MAGI on your tax return from two years prior. Errors do occur, and if the numbers do not match, contacting SSA promptly can prevent months of overpayment.
For anyone within a few years of Medicare enrollment, the brackets deserve a permanent spot in retirement projections, right alongside tax estimates and healthcare spending assumptions. IRMAA is not a penalty or an anomaly. It is a built-in feature of Medicare’s financing structure, and the retirees who budget for it in advance are the ones least likely to be rattled when that first SSA letter arrives.
