Does converting to a Roth in a low-income year really save that much tax?

It can be one of the highest-value moves available. In a year when your income dips, from early retirement, a sabbatical, a business loss, or a gap between jobs, your marginal tax rate may fall into the lowest brackets. Converting Traditional IRA dollars to Roth then means paying tax at those low rates on money that would otherwise be taxed at higher rates during RMD years. You permanently move the money into a tax-free bucket that also escapes future RMDs. The key is to convert only up to the top of your target bracket so you don't spike your own rate. Watch the effect on ACA subsidies and Medicare premiums. Confirm current brackets at irs.gov.