Separate returns are required for some married taxpayers who file a joint federal return.

If one of you was a New York State resident and the other was a nonresident or part-year resident, you must each file a separate New York return. The resident must use Form IT-201. The nonresident or part-year resident, if required to file a New York State return, must use Form IT-203. However, if you both choose to file a joint New York State return, use Form IT-201 and both spouses’ income will be taxed as full-year residents of New York State.