Irmaa Brackets 20254 2025 Income Limits. Irmaa brackets are income thresholds that determine additional medicare premium charges based on your modified adjusted gross income from two years prior. Irmaa directly impacts your medicare part b.

Understanding these thresholds helps you anticipate added costs if your income is over the set limits. The social security administration determines irmaa based on your tax return, and if applicable, you will receive an irmaa letter notifying you of the increased premium amount.