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magician balancing an egg on a paper fan
George Karger—Getty Images/Time & Life Picture Collection

Roth IRAs are in fashion. Many people seem to believe that the Roth’s tax-free nature somehow generates more wealth in the end than other retirement savings options. But Roth IRAs have no magical capabilities.

A simple example of putting $5,000 to work in two types of IRAs—Roth and Traditional—shows there is no difference in the ending values of the two accounts, assuming your tax rate is unchanged between the initial contribution and withdrawal.

If your tax rate does change, the story is different. If your rate goes down, a Traditional IRA does better. And if your rate goes up, then the Roth does better. So neither IRA is a slam-dunk for tax savings: It all depends on whether your tax rate changes, and in which direction.

RMDs May Be No Big Deal

Roths are also touted for their ability to sidestep required minimum distributions. RMDs are the government’s way of making sure you pay taxes on Traditional IRAs. They are calculated as your IRA account balance divided by a “distribution period” corresponding to your life expectancy. You must begin RMDs at age 70 1/2, and include those withdrawals as part of your taxable income.

RMDs can be a nuisance to those with significant savings, and the dwindling few who receive pensions, because they can generate unnecessary taxable income. That is money you don’t need for living expenses, which will be taxed anyway. Even worse, in some scenarios, RMDs plus Social Security can force you into a higher tax bracket.

But RMDs may be a moot point. Many of today’s retirees are tapping their portfolios well before 70½ or relying on Social Security. And for many pre-retirees, the problem won’t be having to take out more than they need—it’s not having enough retirement savings in the first place! The government’s RMD rules won’t force much, if any, “extra” income on them.

Because of the threat of RMDs pushing you into a higher tax bracket, the conventional advice is that you should “top-off” your tax bracket in low-income years of early retirement by doing a Roth Conversion. That means transferring money from your Traditional IRA to a Roth, and paying income tax on the converted amount. You would be choosing to pay taxes now, in hopes that will save you on higher taxes in the future.

Consider the Margin for Error

But conventional rules of thumb can be inaccurate. You have to run your own numbers and, even then, the accuracy of the answers will be limited by your ability to predict your income far into the future. RMDs and Roth conversions lead to some very complex financial scenarios.

Analyzing my own situation using the best retirement calculators shows only modest levels of RMDs into our 90s, with our current 10% to 15% tax bracket unchanged. In theory, I could generate about 2% to 3% more wealth in the end if I did Roth conversions, as long as I paid the conversion tax from non-IRA assets. If I paid the tax from IRA funds, there would be no value in doing a conversion.

However, that 2% to 3% gain is well within the margin of error for retirement calculations. Who knows if I would ever see it? But, in doing Roth conversions, I would see additional complexity and paperwork in my financial life starting right now. Given that, I’m foregoing Roth conversions for the time being.

Roth conversions are unlikely to save you from high taxation of retirement assets. That’s because the total amount you can convert is limited by the number of years you spend in a lower tax bracket and your “headroom” to the next higher bracket.

Still, there are scenarios where Roths can save you money, particularly for those in higher tax brackets. And Roths can be useful to tax diversify your savings. To clarify the issues in your situation, use one or more of my recommended high-fidelity retirement calculators to run your own numbers.

And before you invest too much time in Roth tax tricks, make sure your overall retirement savings rate is on track: that will have a much bigger impact on your long-term financial success!

Darrow Kirkpatrick is a software engineer and author who lived frugally, invested successfully, and retired in 2011 at age 50. He writes regularly about saving, investing and retiring on his blog CanIRetireYet.com.

Read next: Which Wins for Retirement Savings: Roth IRA or Roth 401(k)?