IRMAA stands for Income-Related Monthly Adjustment Amount. It is the mechanism by which Medicare charges higher-income beneficiaries more for their Part B and Part D coverage. SSA uses your modified adjusted gross income (MAGI) from your tax return two years ago.
For 2026 Medicare premiums, SSA used your 2024 tax return. If your 2024 MAGI was over $103,000 single or $206,000 joint, you pay IRMAA tiers ranging from $74.00 to $443.00 in additional monthly Part B premium, plus matching Part D surcharges.
If your income dropped significantly because of a "life-changing event" (retirement, divorce, death of spouse, work stoppage, work reduction, loss of income-producing property), you can file Form SSA-44 to request a reduction. SSA will recalculate based on your current income.