Medicare Part B has a standard monthly premium — in 2025, it's $185.00 per month. But if your income exceeds certain thresholds, you pay considerably more. This additional charge is called the Income-Related Monthly Adjustment Amount (IRMAA), and it catches many beneficiaries by surprise.
How IRMAA Is Calculated
Medicare uses your Modified Adjusted Gross Income (MAGI) from two years prior to determine your IRMAA surcharge. So in 2025, Medicare looks at your 2023 tax return. This lag matters: if you retired or had a large income year two years ago, you may be paying higher premiums now even though your current income is lower.
2025 Part B IRMAA Brackets
| Individual MAGI | Joint MAGI | Monthly Part B Premium |
|---|---|---|
| ≤ $106,000 | ≤ $212,000 | $185.00 |
| $106,001 – $133,000 | $212,001 – $266,000 | $259.00 |
| $133,001 – $167,000 | $266,001 – $334,000 | $370.00 |
| $167,001 – $200,000 | $334,001 – $400,000 | $480.90 |
| $200,001 – $500,000 | $400,001 – $750,000 | $591.90 |
| > $500,000 | > $750,000 | $628.90 |
Part D also has IRMAA surcharges, ranging from approximately $13 to $81 per month on top of your plan premium.
Can You Appeal IRMAA?
Yes — and this is important. If your income has dropped significantly since the two-year lookback period (due to retirement, divorce, death of a spouse, loss of income-producing property, or other life-changing events), you can file a Life-Changing Event appeal (Form SSA-44) with the Social Security Administration to request a lower IRMAA based on your current income.
IRMAA and Medicare Advantage
Even if you're enrolled in a Medicare Advantage plan, you still pay the Part B premium (and IRMAA if applicable). Your Medicare Advantage plan premium is in addition to — not instead of — the Part B premium. Some Medicare Advantage plans offer a "Part B giveback" benefit that reduces your Part B premium, which can partially offset IRMAA for some beneficiaries.
Planning Ahead
If you're approaching Medicare eligibility, income planning in the years before enrollment can make a meaningful difference in your premium costs. Talk to your financial advisor about Roth conversions, capital gains timing, and other strategies that may reduce your MAGI. And if you have questions about how IRMAA affects your Medicare costs, call us at (530) 395-5309.