I’m 58, single, and Medicare is still seven years away. It already matters to me, though, because of one rule: the premium I’ll pay at 65 is set by the income on the tax return I file for the year I turn 63. Those are exactly the years I’d want to do Roth conversions. So I built a small IRMAA calculator that answers the narrow question first: given a year’s income, which Medicare surcharge tier does it land in, what does that cost, and how close is the next cliff?
It’s free, there’s no signup, and it runs in your browser. You enter three things and it answers right away.


