Irmaa 2025 Projection Lines. Each irmaa tier has a corresponding marginal tax rate that determines the additional premium part b and part d surcharges. The 2025 irmaa brackets are expected to affect even more retirees than the current brackets.
Each irmaa tier has a corresponding marginal tax rate that determines the additional premium part b and part d surcharges. For most people, the 2023 tax data would have gone into the 2025 irmaa calculation.