How much should I convert each year?

A common approach is to fill your current tax bracket — convert up to the top of it, but not past — while staying under the IRMAA and ACA cliffs. The right amount depends on your other income that year.

Do Roth conversions affect Medicare premiums?

Yes. A conversion raises your modified AGI, which can push you into a higher IRMAA tier — and IRMAA looks back two years, so a conversion today can raise your Medicare premiums two years later.

Guide

The Roth conversion ladder

Converting traditional savings to Roth in low-income years can cut your lifetime tax bill — if you fill the right brackets and avoid the cliffs.

Updated July 11, 2026

The idea in one paragraph

In the low-income years between retiring and starting Social Security or RMDs, your tax brackets may be nearly empty. Converting traditional 401(k)/IRA money to Roth in those years taxes it at a low rate now, so it grows and comes out tax-free later — and shrinks the RMDs that would otherwise force taxable income at 73 or 75.

Done across several years, that's a “ladder”: convert an amount each year that fills your target bracket without spilling into the next one.

The cost is a blended rate, not a marginal one

A conversion that crosses a bracket boundary is taxed partly at each rate. The honest cost is the span-integrated effective rate over the amount converted — not the top marginal rate times the amount, which overstates it. Our Roth conversion calculator computes it the correct way and shows how much room is left in your current bracket.

Watch the cliffs conversions can trigger

Extra income from a conversion counts toward two hard cliffs. It can push your Medicare IRMAA into a higher tier two years later, and — if you buy health coverage on the ACA marketplace — it can cost you the entire premium tax credit above 400% of the poverty line. Both are worth checking before you convert.

Use the IRMAA and ACA subsidy calculators to see whether a planned conversion crosses either threshold.

Related free calculators

Frequently asked

How much should I convert each year?: A common approach is to fill your current tax bracket — convert up to the top of it, but not past — while staying under the IRMAA and ACA cliffs. The right amount depends on your other income that year.
Do Roth conversions affect Medicare premiums?: Yes. A conversion raises your modified AGI, which can push you into a higher IRMAA tier — and IRMAA looks back two years, so a conversion today can raise your Medicare premiums two years later.