When U.S. Citizens Living Abroad Owe U.S. Tax
You may 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.
Overseas American Citizens: When You Need to File a Tax Return or Pay U.S. Taxes
U.S. citizens have to file a tax return with the IRS every year, irrespective of the fact that they may have lived or worked outside of the country for the year in question -- and they may owe taxes, as well.
How Do I Value My Foreign Income for U.S. Tax Purposes?
Given that the U.S. takes its citizens foreign income into account, you'll need to figure out the appropriate exchange rate for calculating it in U.S. dollar terms.
How Does My Marriage to a Foreign Citizen Affect My Taxes If We Don't Live in the U.S.?
The choice between "married filing jointly" and "married filing separately" takes on new significance when living abroad with a non-U.S. spouse.