Foreign Income Earned Credit. Basically since the US is one of two countries in the world to still collect taxes from people living abroad, you have to file taxes every year still but it usually amounts to a net of $0.00 as it's written off under double-tax agreements with Germany.
The Foreign Earned Income Exclusion essentially sets your tax rate to 0% for the first $108k of earned income. It has no effect on earned income in excess of this threshold, or on unearned income such as investment income.
The Foreign Tax Credit subtracts your foreign tax liability from your US tax liability. In other words, you only pay US taxes to the extent they exceed the foreign tax rate. You can use it on any type of income, but you only get a benefit if the foreign country actually taxes the income.
You may not double dip: So if you choose to take FEIE for some part of your income, you cannot take FTC on the same part of your income. However, you can take FTC to the extent you have income not eligible for FEIE.
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