Medicare Looks Back Two Years. A Roth Conversion at 63 Lands on the Premium at 65. The Same Conversion at 62 Never Shows Up

A Roth conversion at age 63, rather than age 62, can trigger higher Medicare premiums when coverage begins at age 65 because Medicare generally uses income from two years earlier to calculate income-related monthly adjustment amounts. The article highlights timing risk for retirement tax planning: conversion income can create a monthly Medicare surcharge even when an otherwise identical earlier conversion would not affect premiums.