Income-Related Monthly Adjustment Amount (IRMAA) is a surcharge applied to Medicare Part B and Part D premiums for high-income beneficiaries. The calculation for 2025 premiums is based on the beneficiary’s modified adjusted gross income (MAGI) from their 2023 tax return. This two-year look-back period means that income reported two years prior determines the premium adjustments for the current year. For example, if an individual’s 2023 MAGI exceeds a certain threshold, they will pay a higher premium for Medicare Part B and Part D in 2025.
The IRMAA system ensures that those with greater financial resources contribute more to the cost of Medicare. This helps to keep the program sustainable and accessible for all beneficiaries. Understanding the income thresholds and how MAGI is calculated allows individuals to plan their finances effectively and potentially mitigate future premium increases. This system has evolved over time, with adjustments to the income brackets and surcharge amounts to reflect changes in the cost of healthcare and inflation.