Thank you so much for help. I do not have income from US source at all. If I don't need to file 1040NR, then should I file 1040 for the last 1 full year, or only partial year of the US citizenship? If I need to file for the partial year, can I use the standard reduction?
Still, I have a question regarding this matter. I also got advice form other tax expert.
"U.S. tax residency – Green card test. You are a resident, for U.S. federal tax purposes, if you are a lawful permanent resident of the United States at any time during the calendar year."
https://www.irs.gov/individuals/international-taxpayers/us-tax-residency-green-card-test
He said this applys to the US citizenship also, so he advised me I need to file 1 full last year as a resident.
I would appreciate it if you could help me clarify this.
Thank you again.
There are special rules for your tax filings in the year of expatriation. You must file a dual-status return, though it sounds like the 1040NR portion in your case will only contain zeros for the income and tax figures.
You are not able to claim the standard deduction when you file a dual-status return, but you can itemize deductions if any apply in your situation.
You must also file Form 8854, the Initial and Annual Expatriation Statement, with your dual-status return.
TurboTax doesn't include form 1040-NR and doesn't support the dual-status return online, but with our desktop product you can complete the 1040 portion in our software, if desired. You can learn a bit more about filing this way here: How should I file my taxes as a dual-status alien?
I would suggest finding a tax professional with experience in filing the Initial Expatriation Statement (form 8854) with the Dual-status return to assist you in this tax filing obligation to ensure full compliance.