5. Adjustments to Part B Premiums and IRMAA Brackets

While we often focus on benefits and drug costs, your monthly Medicare Part B premium demands equal attention. Part B covers your outpatient care, doctor visits, and durable medical equipment. The standard Part B premium undergoes an annual adjustment based on inflation and the projected healthcare costs of the entire Medicare pool. As complex therapies—particularly new Alzheimer’s treatments and costly specialty infusions—enter the Medicare ecosystem, the baseline Part B premium faces steady upward pressure.

However, the most severe financial shock comes in the form of the Income-Related Monthly Adjustment Amount, or IRMAA. If your income exceeds certain thresholds, the government requires you to pay a surcharge on top of your standard Part B and Part D premiums. This surcharge can easily add hundreds of dollars a month to your healthcare costs.

IRMAA is notoriously tricky because it operates on a two-year lookback period. The premiums you pay in 2026 are based on the Modified Adjusted Gross Income (MAGI) reported on your 2024 tax return. Many retirees get trapped by this lag. If you sold a business, liquidated a highly appreciated real estate property, or executed a massive Roth IRA conversion in 2024, that artificial income spike will trigger heavy IRMAA surcharges in 2026.

The brackets dictating these surcharges are adjusted annually for inflation. While inflation indexing helps protect those whose income rises merely due to Social Security cost-of-living adjustments, large capital gains will still push you into higher penalty tiers. If you receive an IRMAA notification from the Social Security Administration (SSA) and your income has since dropped due to a life-changing event—such as retirement, divorce, or the death of a spouse—you must act immediately. You can file Form SSA-44 to request a new initial determination, potentially saving yourself thousands of dollars in unnecessary premium surcharges.