The Income-Related Monthly Adjustment Amount (IRMAA) is an additional charge added to the standard Medicare Part B and Part D premiums for beneficiaries with higher incomes. This adjustment ensures that individuals with greater financial resources contribute more to the Medicare program, aligning their contributions with their ability to pay. Understanding IRMAA is crucial for high-income retirees and those approaching Medicare eligibility, as it directly impacts healthcare costs in retirement. Understanding IRMAA Medicare, the federal health insurance program primarily for individuals aged 65 and older, consists of several parts: Part A: Hospital insurance covering inpatient hospital stays, skilled nursing facility care, hospice care, and some home health services. Part B: Medical insurance covering outpatient care, doctor services, preventive services, and medical supplies. Part D: Prescription drug coverage. While many beneficiaries receive Part A without a premium, Parts B and D typically require monthly premiums. For individuals with higher incomes, IRMAA increases these premiums based on their modified adjusted gross income (MAGI) from two years prior. For example, 2025 IRMAA determinations are based on 2023 income levels. 2025 Income Thresholds and IRMAA Brackets The Social Security Administration