Medicare Premiums Set by 2025 Tax Returns for 2027 Costs

The 2025 tax return affects your 2027 Medicare premiums due to the Income-Related Monthly Adjustment Amount (IRMAA). Married couples may see their combined monthly Part B costs increase from $203 to as high as $974 based on crossed tiers. IRMAA surcharges apply to income from sources like Roth conversions and capital gains, and relief is only granted for specific life events via Form SSA-44. This matters for ordinary investors as high-income retirees could face significantly higher Medicare costs based on past income adjustments.