I don’t know of any specific software, however you could simply use a general tax program, figure your taxes including the conversion (conversion taxable amount adjusted for any IRA basis), then figure your taxes without the conversion. The difference in total taxes divided by the gross amount of the conversion is the marginal tax rate for the conversion itself. Note that if the conversion amount is large, the combined marginal rate could reflect different rates for different parts of the conversion. If that is the case, you would just enter different conversion amounts to see how the marginal rate changes. Finally, if you are on Medicare, a conversion done this year might expose you to IRMAA surcharges in 2021, which is a tax due 2 years later but attributed to the conversion amount.

• Flag as spam
• Log in to Reply