How a Resident Alien Is Taxed in the United States
Just because you're not a U.S. citizen doesn't mean you don't owe taxes to the IRS. Whether or not you owe taxes depends on how much time you spend in the U.S.
When U.S. Citizens Living Abroad Owe U.S. Tax
You might not owe any actual tax, but if you're a U.S. citizen, you probably need to file a tax return no matter where you live.