Sigh, this always comes up and I’ve never met a single person who actually had to pay taxes. My brother in law was out of the country for a decade and a few other friends lived in Europe and never paid.

Has anyone on HN paid US taxes living abroad?

You do still have to file a tax return, which can be a bit complicated if you have foreign income. But if you work in Europe, you're right that you likely won't have to pay any actual US taxes. You can take the European tax paid as a foreign tax credit against the US taxes, and that almost always zeroes it out, since European countries mostly have higher tax rates. That was the case for me, anyway.

You will have to pay some tax if you work in a country whose tax rates (for your bracket) are lower than US federal tax rates. That can be the case for Americans working in places like Hong Kong or the Bahamas.

This is often also the case in Switzerland.

California’s residency requirements are quite strict, and they don’t offer foreign tax credits, so if you’re planning to go back after a few years you’re effectively being double-taxed on the state income.

I worked with a guy in the UK who constantly lamented this.