Going through the back door can pay off for high-income retirement savers.

We’re talking about the backdoor route into popular Roth individual retirement accounts, which offer tax-free income in later life.

The front door into Roths is shut for many investors. Married couples earning $191,000 or more and singles earning $129,000 or more in 2014 are barred from contributing directly to Roth IRAs.

But there’s a simple detour that works for many of them. They can put money into a traditional IRA—and then roll that into a Roth IRA, getting all the benefits.

More than 40% of the Silicon Valley executives working with adviser Bijan Golkar of FPC Investment Advisory Inc. in Petaluma, Calif., do this year after year, he says. Roth IRAs are “a great tool” for these clients, who are likely to be in high tax brackets even in retirement because of hefty 401(k) accounts, he says.

With a Roth IRA, contributions are made with after-tax dollars, but earnings compound without tax and can be withdrawn tax-free in retirement. With a traditional IRA, in contrast, qualifying savers get an upfront tax deduction but owe tax when money is withdrawn.

Most high earners who can’t contribute directly to a Roth also can’t make a deductible IRA contribution. For instance, there’s no deduction if you are covered by a retirement plan at work and have 2014 income of at least $116,000 on a joint return or $70,000 as a single filer. So for those investors, a traditional IRA is ho-hum.

But high earners are still allowed to contribute to a traditional IRA, and that’s the first step in the indirect route to a Roth IRA. The next step, which might occur as soon as a few days later: Convert that traditional IRA to a Roth, which is a move available to all.

There’s one big caveat: This strategy works best for people who don’t already have money in traditional IRAs. That’s because in conversions, earnings and previously untaxed contributions in traditional IRAs are taxed—and that tax is figured based on all your traditional IRAs, even ones you aren’t converting.

For an investor who doesn’t already hold traditional IRAs, creating one and then quickly converting it into a Roth IRA will cost little or nothing in tax, because after a short holding period there’s likely to be little or no appreciation in the account.

But if you already have money in traditional IRAs, particularly ones for which you took a deduction, you could face a far higher tax bill on the conversion.

“That is definitely a trap that people fall into,” says Jeffrey Levine, a CPA with Ed Slott & Co. in Rockville Centre, N.Y.

One possible workaround, he says, is to roll older traditional IRAs into your 401(k) plan, if the plan allows. Then converting a new IRA into a Roth will cost you taxes on only the earnings, if any, of the new account.

Original Article: Wall Street Journal