I think too many people talk about Roth conversions as if they’re automatically a smart move. They’re not.
A Roth conversion is simply moving money from a tax-deferred account, like a traditional IRA, into a Roth account and paying tax on that amount now. The real question is whether prepaying that tax helps your long-term plan.
In my view, there are 3 big effects to think about.
First, you’re paying tax now instead of later. That can be a good trade, or a bad one. It comes down to your current marginal tax rate versus the tax rate that would apply if those dollars stayed tax-deferred. And that analysis is rarely as simple as just looking at your tax bracket.
For retirees, the real marginal rate can be pushed around by things like ACA premium credits, Social Security taxation, and Medicare IRMAA. For married couples, I also think it’s important to remember that the surviving spouse often ends up in a worse tax situation later. And if a big chunk of IRA money is likely going to charity, that argues against converting, because paying tax now to avoid a future 0% rate is not much of a strategy.
Second, a conversion can let you use taxable-account dollars to effectively buy more Roth space. That matters more than many people realize.
If you pay the conversion tax from a taxable account instead of withholding it from the IRA, you get more money into the Roth. In plain English, you’re moving dollars from a less tax-efficient bucket into a more tax-efficient one. Over a long stretch of retirement, that tax-free compounding can be meaningful.
This is one of the biggest points people miss. The usual conversation gets stuck on “Will my future tax bracket be higher or lower?” That matters, of course. But I’m also looking at whether we can improve the location of assets and reduce ongoing tax drag over time.
Third, conversions reduce future RMDs. That can help, especially for households that expect to reinvest part of those RMDs rather than spend them.
Smaller RMDs don’t just mean less forced income. They can also mean fewer dollars pushed out into taxable accounts where interest, dividends, and realized gains create a steady drag. If the money can stay inside a Roth instead, that’s often cleaner and more efficient.
That said, I appreciated the reminder that Roth conversions usually do not solve the biggest retirement risks.
They don’t fix bad market returns early in retirement. They don’t fix overspending. They don’t fix large healthcare shocks or other unexpected expenses. In other words, they usually don’t dramatically improve the odds that you won’t run out of money.
That’s an important distinction.
A smart conversion strategy may do a better job of improving the after-tax value of what’s left, especially for heirs, than improving the retiree’s core financial security. I think that’s a more honest way to frame it.
So when do I think conversions fit best?
Usually in years when income is temporarily lower, before RMDs start, and when there’s a clear tax window worth using. Early retirement often creates those windows. Once Social Security and RMDs are fully online, flexibility usually shrinks.
I also think Roth conversions need to be viewed as part of a broader withdrawal plan, not as a standalone tactic. The order you spend from matters. The mix of taxable, tax-deferred, and Roth assets matters. Your health, your charitable intent, your heirs, and your time horizon all matter.
That’s why I’m skeptical when I hear blanket advice on conversions.
Sometimes they’re absolutely worth doing.
Sometimes they’re a wash.
And sometimes they’re just a way to write a bigger check to the IRS sooner than necessary.
As always, the right answer is not “Roth conversions are good” or “Roth conversions are bad.” The right answer is: what problem are we trying to solve, and at what tax cost?