I'm living in NYC for 3 years to complete a graduate medical education program at a university hospital (aka "residency"), which pays me a salary. The hospital appoints me on an annual basis limited to the 3-year program. My parents own a house in Illinois which is my permanent address. I expect to return to Illinois, get an Illinois medical license, and get a permanent job in Illinois upon completion of my residency program. My entire family lives in Illinois. My parents own and manage real estate located there and I make some W-2 income during residency for doing work for the family business. I have to file in NY and IL. It would be advantageous to file as an IL resident and NY nonresident, if OK. What do you think? Thank you very much.

You're a NY resident, sorry. I am assuming that you spend more time in NY than IL, and that's what makes the difference. And if you are currently renting an apartment in NYC, then that seals the deal. So you file as a NY resident, and also as an NY City resident. I see no need to file IL taxes, unless you are physically present in IL when you earn the money from your family business.

Thank you ebaines. Follow-up question: I read a thread discussing whether a foreigner working in NYC on a green card could file as a nonresident, and the answer ultimately was yes because NY determines tax residency based on intent (citing In the Matter of the Petition of Patrick Gallagher, in the State of NY Division of Tax Appeals). The thread distinguished New York from the IRS, which decides tax residency on the grounds of stuff like amount of time spent and significance of income earned. Based on that thread, I'd expected the answer to be that I may file as a NY nonresident. Any further take on this? Thanks very much!

You could make the argument that you are a student and thus a non-resident. Why not submit an appeal to there NY State tax department and ASK?

The worst that can happen is that they say NO!