It's low. There's no discussion in Washington of taxing them. And even if Congress did tinker with Roth IRAs someday — perhaps taxing withdrawals or eliminating Roths altogether — such changes probably wouldn't affect money already invested, say tax experts. "There would certainly be an uproar," says Tax Policy Center co-director Eric Toder.
If you're still worried about this theoretical risk, remember that your alternatives, such as pretax contributions to a traditional IRA or 401(k), carry risks too: Tax rates could be higher when you make withdrawals. To hedge your bets, it's good to keep assets in accounts with different types of tax treatments.
By CNN Money Kate Ashford