In mid-2024, I moved from Massachusetts to New York, where I have since lived and worked. My wife remained in Massachusetts, living and working there for the entire year, until we resolved our housing situation in early 2025. We plan to file our federal taxes jointly. How should we file our state income taxes for Massachusetts and New York?
You can file your federal return jointly, but you will have to file separate Massachusetts return and it would probably be best if you filed New York separate (sincve you are the only one who had New York income and you are required to prepare the "mock' single return to prepare the Massachusetts return.
Massachusetts: If married taxpayers have a Massachusetts residency tax year that begins and ends on different days, they must file married filing separately, assuming each spouse is required to file.
New York: In nearly all cases, you must use the same filing status that you used on your federal return. The only exceptions to this rule apply to married individuals who file a joint federal return and one spouse is a New York State resident and the other is a nonresident or part-year resident. In this case you must either file separate New York State returns or file jointly, as if you both were New York State residents.
See How do I prepare a joint federal return and separate state.