Also called: Roth conversion ladder
Moving money from a pre-tax IRA or 401(k) into a Roth account. The pre-tax amount converted is added to that year's ordinary income; later growth and qualified withdrawals are tax-free.
There is no income limit and no dollar cap on conversions. A conversion cannot be undone: recharacterizing a conversion was repealed for conversions made after 2017.
Conversions reduce future required minimum distributions, but the added income can raise Medicare premiums two years later, reduce ACA subsidies, and make more Social Security taxable in the conversion year.