Wherever you decide to go, the IRS will go with you.
"U.S. citizens continue to file taxes in the U.S. and are taxed on worldwide income," said Paul Dailey, a CPA and partner at Citrin Cooperman in New York who specializes in foreign tax planning.
In fact, because you'll be a resident of two countries, you'll need to file — and possibly pay up — in both.
The good news is that it doesn't necessarily mean you'll pay double.
"Whatever you pay in taxes over there, you will be given credit for back home," Dailey said.
That's because retirees are eligible to take advantage of something called the foreign tax credit, which keeps you from paying taxes twice on the same kind of income.
Also, if you plan on working while abroad, the IRS will allow you to exclude some of your earnings from being taxed, provided you meet a few criteria. For 2016, Daily said, you can earn up to $101,300 in a foreign country and not have it taxed by the U.S.