I worked full time with my OPT in New York City in 2015. I stayed in NYC from Jan to June and moved to New Jersey and stayed there for the rest of the year. I did not earn from New Jersey state.

For federal tax case, I should file as a resident alien since 2015 is my 6th calendar year in US using F1 visa. But I think the residency rule is different when filing state and city taxes.

In this case, should I file state and city taxes for New Jersey state? If so, should I file as a resident, non-resident or partial resident? If not, how should I file tax for New York state and NYC? (Note the company already withheld all my state tax for NYS.)

You will file as a part-year resident of New York state AND NYC, then as a non-resident for the rest of the year.

You will file the New Jersey return as a part-year resident. You will owe NO New Jersey tax because you get a tax credit for the taxes paid to New York, and New York's tax rates are higher than New Jersey.

If you need professional help preparing the return, please email me at the email address in my profile.

Give the residency rule for NYS at https://www.tax.ny.gov/pit/file/pit_definitions.htm.

I can claim that I'm a non-resident for taxing purpose in NYS as my permanent home address is out of US and I do no intend to have it as my permanent home address, similar for NYC and NJ state.

Also should I even file a tax statement for NJ state if my permanent address is out of NJ and I did not earn from NJ?

Yes, you CAN do that. My error.

Yes, you can do that. My error!