Although we can’t refund correctly paid U.S. Social Security taxes and contributions, you still may be able to get benefits based on those tax contributions. We have agreements with 25 countries that improve Social Security protection if you spend part of your working life in the United States and an agreement country. These agreements can help you if you otherwise would not be eligible for benefits in either country. The agreements also eliminate you having to pay taxes to both countries on the same earnings.
International Programs: International Programs and Resources
International Programs: International Agreements
Service Around the World
U.S. Tax Guide for Aliens
Withholding of Tax on Nonresident Aliens and Foreign Entities