I work in NY but live in NJ. Same with my husband until he moved to MI for a new job in the middle of last year. We used to file NY jointly as non-resisdent and NJ as resident. First of all, since MI has lower state tax, can he claim he's resident of MI although we still have our house in NJ? Second, if we file Federal tax jointly, do we need to file state tax jointly in every state (NY, NJ and MI) although I don't have any income in MI?

First, he can claim to be a MI resident if that's his principal abode. The first test to determining one's principal abode is where does he spend the most time and has he taken steps to establish his new residency? If he is spending more than 183 nights in MI then he can argue that it's his state of residency, and to bolster that claim it helps if he has estanblished a residence either by buying or renting a property. Also if he has a car registered in MI, and registered to vote there, it jeps complete the argument.

As for filing taxes - you should still file jointly for federal. Complet the non-resident NY return as usual. For NJ you can file as Married fling Separate if your husband is a resident of another state for the entire year and has no NJ-source income (no wages from an NJ employer or other NJ income). So for the first year you will file a joint return, using NJ-1040NR, to separate out his income earned after he relocated to MI. Then in subsequent years he doesn't file at all and you file NJ-1040 as Married Filing Separately.

For MI he files a part-year resident return for 2012. It seems that MI will require him to file a joint return, which means it will include your income as well as his. But you can take a credit for income taxes paid to other jurisdictions (in your casethat would be NY and NJ), and the consequence is that you will not actually have to pay any income tax to MI on your earnings.

Hope this helps!