Maybe, if you're worried that you'll outlive your money. The cost of living in many foreign countries is much lower than that in the U.S. That means your retirement kitty can last longer. But there are many factors to consider. Some include:
Taxes. Many countries have tax treaties with the U.S. that help to reduce the chances you'll be taxed twice. (Google expat sites for a given country and you'll find the info you need.) But even if you're living abroad full time, you'll still have to file a U.S. tax return.
If you work in retirement while you're living overseas, you can claim the Foreign Earned Income Tax Credit. In 2010, this allows you to exclude the first $91,400 you earn in the foreign country from U.S. taxes. Earn more than that amount and Uncle Sam is going to take his cut of your earnings. Pension income from U.S. sources is also going to be taxed, no matter where in the world you happen to be living.
Health care. It's a big issue - and potentially a big problem. Despite all the drawbacks with the health-care system in the U.S., the quality of care there is among the highest in the world, while some other countries are below par. Unfortunately, it's those countries with the lowest cost of living that frequently have the worst medical care.
Another huge issue for expat retirees is that Medicare coverage does not extend beyond U.S. borders. You'll either have to return to the U.S. for any care or budget to pay for care or insurance in your new home away from home. Either way, it can be more expensive than you bargained for.
Exchange rates. You'll be subject to currency risk. If your retirement income is in U.S. dollars, you could suffer if the country you live in sees its currency's value rise against the dollar.
Bill paying. Depending on the country, you may find it nearly impossible to open a local bank account - and once you do, it may not be set up to handle deposits (such as Social Security checks) in U.S. dollars. Many expats deal with this problem by maintaining a U.S. bank account and then paying for a wire transfer (and transfer to local currency) a few times a year.
And if you plan to just rely on your U.S. bank, you'll ring up some sizable ATM fees anytime you want to get local currency by tapping your U.S. account. It can often cost you more than $5 per transaction, and many countries limit the amount foreigners can withdraw on a daily basis. As a result, you'll be stuck paying the nuisance fee on smaller withdrawals.
Most retirees who live overseas keep their credit cards based in the U.S. and make online bill payments. That's generally a good way to keep costs down.