When does tax liability in the USA begin if you receive a green card?

If you win a green card in the lottery or receive one through marriage, you don't usually emigrate to the US immediately; you just fly over to pick up the green card. As far as I know, you then have one year (up to two years upon application) before you have to move permanently. During…

If I win a green card and then emigrate to the USA after two years, do I have to pay taxes in the USA beforehand?

Unlike Germany and almost all other countries, the US tax system is based on worldwide income. Anyone with US citizenship or a green card must pay US tax on their worldwide income, even if they don't live there. At the same time, however, Germany wants income from Germany to be taxed in Germany. I only…