IRMAA

Terry Says

Yes, you would be charged for both Part B and D. And if you earned more than the IRMAA adjustment levels for that year, then you would pay a surcharge.
They get the earnings number from your tax return — the line for Modified Adjusted Gross Income.

Ask your tax preparer to explain that MAGA number — and if you earned less in succeeding years, they will no longer charge a surcharge. You can contact Social Security to dispute it.
Please read this article: https://www.terrysavage.com/irmaa-increases-medicare-premiums/