There’s now a big danger if you’re rolling money over from one IRA into another IRA, as a result of a decision from the U.S. Tax Court.

Under federal law, you can only do one IRA-to-IRA rollover per year. If you try to roll over more than one IRA in a 365-day period, it’s considered a distribution, and you’ll be subject to significant taxes and penalties.

In the past, the IRS has told taxpayers that this means you can’t roll over the same IRA within a year. So if you rolled your Fidelity IRA over to Schwab, and you later wanted to roll the same IRA over to Vanguard, you had to wait at least 365 days.

But the Tax Court says this is wrong, and in fact you can’t roll over more than one IRA per year even if they’re different IRAs.

So if you had two IRAs at Fidelity, and you wanted to roll them both over to Schwab, you’d have to roll one over, and then wait a whole year to roll over the second one.

There’s an easy solution to this problem: Instead of rolling the funds over (having them made payable to you and then depositing them at the second institution), move them with a direct trustee-to-trustee transfer. As long as the funds move directly to the second institution, and you never touch them, it’s not considered a rollover.

But you have to be very careful and make sure that the formalities are followed and the first institution doesn’t actually send you any money. Otherwise, it could be a tax nightmare.