Investors can convert a traditional IRA into a Roth, so long as they pay taxes-at current rates-on the balance being converted. But financial advisers warn that it can take a minimum of five years of investment gains for a Roth to recoup the amounts lost to taxes, and 10 years or more for the Roth to yield significant gains, which isn’t ideal for Boomers and investors in their 50s and 60s facing imminent retirement.