@vista25 correct
the 2025 IRMAA charge is based on her 2023 income and filing status
the 2024 filing status won't be known to Medicare at the point that the 2025 IRMAA charge is determined.
Medicare will determine the 2025 IRMAA charge in the 4th quarter of 2024 and your Mom won't be filing the 2024 tax return until April, 2025. That is why the determiniation is based on 2023 filing status and income - it's the last data point Medicare can obtain from the IRS to determine the 2025 IRMAA charge.
While you will be locking in your Mom's 2023 income shortly, the IRMAA brackets are adjusted for inflation - . and this is the frustration - the inflation year goes from Sept 2023 - August 2024. If inflation runs 0% for the next 11 months, then the IRMAA bracket would be $210,000. if the inflation runs 3% for the next 11 monrgs, then the IRMAA bracket would be $212,000. Heaven for bid deflation sets in, the bracket could be less than $210,000. please read the website in the link I provided previously.
