If one is a citizen and leaves the US, one has to renounce citizenship at an office outside the US and file form 8854 if necessary with the IRS to pay the expatriation tax. Are there other forms?
If one has a green card and leaves the US, one has to file form I-407 (not sure whether you do this inside or outside the US) and also form
8854 if necessary (long term green card holders are still subject to this tax).If one is on F-1 or H-1B and elected to file a 1040 instead of 1040- NR, what do they have to do to tell the US they are gone?