Also called: IRMAA-aware bracket fill
A RetIQ conversion and drawdown mode that fills a chosen tax bracket each year but stops before crossing the next Medicare IRMAA threshold.
Plain bracket filling can push MAGI a few dollars over an IRMAA cliff and cost more in premiums than the conversion saves. Smart Fill uses the smaller of the bracket room and the room under the selected IRMAA tier.
Both the tax brackets and the IRMAA tiers it fills against are inflated forward year by year with your inflation assumption.