For example, let's say you have a pretax IRA of $20,000 and you made a non-deductible IRA contribution of $6,000 in 2022.
Of course, the bigger your pretax IRA balance, the higher percentage of the conversion will be taxable, May said.
Alternatively, a larger non-deductible or Roth IRA balance reduces the percentage.
But here's the kicker: Taxpayers also use the Form 8606 to report non-deductible IRA contributions every year to establish "basis" or your after-tax balance.
Typically, he aims to "fill up a lower tax bracket," without bumping someone into the next one with Roth conversion income.