When should you not do a Roth conversion?

A Roth conversion may not fit if you expect a lower tax bracket in retirement, if you would have to pay the tax from the converted money, or if the added income would push you across a Medicare or Marketplace threshold. It can also be a poor fit if you plan to leave pre-tax money to charity.

A conversion is a trade: tax now for different tax treatment later. That trade helps some households and costs others, and the only way to know which one you are is to look at several years of your own return. This page lists the situations where a conversion deserves a second look. For the other side, see our answer on when to do Roth conversions.

What situations make a Roth conversion a poor fit?

A conversion may be a poor fit when its costs outweigh the benefit. That usually means you expect a lower bracket later, you cannot pay the tax from outside the IRA, the added income triggers another cost, or the money is meant for charity. Each case has its own test.

Should a 65-year-old do a Roth conversion?

Sometimes. At 65, Medicare begins and income-related premiums look back two years, so a conversion at 65 can reach your premiums at 67. Social Security timing and the years left before required distributions also matter. The answer comes from your own numbers, not from the age alone.

A 65-year-old who has not claimed Social Security and has eight or ten years before RMDs may have room to convert in planned amounts. One who has already claimed, or who sits close to an IRMAA threshold, may have much less. Our guide to the Roth conversion window explains how the room is measured.

What is the biggest Roth conversion mistake?

Paying the conversion tax out of the IRA itself is the most common one. Withholding from converted money shrinks the amount that reaches the Roth, and if you are under 59½ the withheld part can trigger the 10% additional tax. Paying the tax from a taxable account avoids both problems.

Close behind is an unplanned income year. A bonus, a vested equity grant or a deferred compensation payout can use the bracket room you meant for a conversion. A third mistake is converting before the year’s required minimum distribution has been taken, when the RMD has to come out first.

Wondering whether a conversion fits your numbers? Bring last year’s return and your account statements to a free 30-minute conversation with Robert Boeck. We will look at your brackets, your Medicare and coverage costs, and your giving plans, and list the questions to take to your CPA. No products and no pitch. Schedule a free 30-minute conversation

How do you decide whether a conversion fits?

Start with three questions: what is your taxable income in each year of the window, what other costs rise when income rises, and where would the tax come from. If the answers show room, a conversion may be worth testing. If they do not, waiting or converting less may fit better.

A hypothetical illustration shows the shape. Imagine a couple a few years from retirement with a large pre-tax balance. They list each year, income by source, their Medicare years and their giving. One year looks open. Another carries a deferred compensation payout. A third is the year Social Security starts. The map shows which years a conversion would use room and which it would crowd. This example is for education only and is not a projection or a recommendation for any household.

What are the limits and risks?

Conversions cannot be undone, tax law changes, and every benefit comes with a cost. Results vary by individual circumstances, and a plan that fits one household may not fit another. Weigh these limits before you convert, and confirm each with your CPA.

• Tax is due now. The converted amount is ordinary income in the year of the conversion.
• Recharacterization is not available for conversions made after 2017.
• Other costs can rise. Medicare premiums, Marketplace credits and the taxable share of Social Security all respond to income.
• Future rates are unknown. A later bracket may be higher or lower than expected.

How does your CPA fit in?

Your CPA prepares your return and can estimate the full tax effect of a conversion, including state tax. The retirement income side of the plan supplies the year-by-year income map, the Medicare years and the giving plans. Settle the amount with your CPA before you convert, since the decision stands once it is done.

Source and as-of date

The rules above reflect these sources as read on October 26, 2026: IRS: Retirement plans FAQs regarding IRAs for conversions and the end of recharacterization, IRS: Roth IRAs, IRS: Premium tax credit overview, and SSA: Medicare premiums. Tax law changes. Confirm current rules with your tax professional before acting. This page is educational and is not tax advice.

What should you do next?

The cost of a wrong conversion arrives in your return and, two years later, in your Medicare premium. The fastest way to find out whether yours fits is to put your own numbers in front of someone who models it every day.

In a free 30-minute conversation, Robert Boeck will walk through your income by year, your coverage costs and your giving, and tell you what to test with your CPA. There are no products and no pitch, and your CPA is welcome on the call. Schedule your free 30-minute conversation. If you would like a starting point first, the free Risk Analysis takes a few minutes.