Sort of. US citizens owe US taxes on their worldwide income, no matter the source. US citizens working abroad also owe taxes to the country they work in. However, the US has tax treaties with many countries that cover how each countries’ citizens are taxed.
If a US citizen earns income in these countries, they may be able to deduct any taxes paid out to the other country against their US tax bill. (And since US tax rates are low compared to many of these other countries, this often results in zero US taxes owed.)
I also heard US citizens will always have to pay income tax even if they are working abroad and had to pay that country’s income tax already.
Sort of. US citizens owe US taxes on their worldwide income, no matter the source. US citizens working abroad also owe taxes to the country they work in. However, the US has tax treaties with many countries that cover how each countries’ citizens are taxed.
If a US citizen earns income in these countries, they may be able to deduct any taxes paid out to the other country against their US tax bill. (And since US tax rates are low compared to many of these other countries, this often results in zero US taxes owed.)