§ 1327. Change of resident status during year. (a) General. If an individual changes his status during his taxable year from city resident to city nonresident, or from city nonresident to city resident, he shall file one return as a city resident for the portion of the year during which he is a city resident, and a return under a local law authorized by article thirty-B of this chapter for the portion of the year during which he is a city nonresident, subject to such exceptions as the state tax commission may prescribe by regulation.

(b) Trusts. If the status of a trust changes during its taxable year from city resident to city nonresident, or from city nonresident to city resident, the fiduciary shall file one return as a city resident trust for the portion of the year during which the trust is a city resident trust, and a return under a local law authorized by article thirty-B of this chapter for the portion of the year during which the trust is a city nonresident trust, subject to such exceptions as the state tax commission may prescribe by regulations.

(c) Computation of net state tax. When an individual or trust changes resident status during the taxable year, the net state tax shall be the net state tax determined as if such individual or trust were a state resident for the entire taxable year, multiplied by a fraction the numerator of which is such individual's or trust's New York adjusted gross income for the period of residence, computed as if the taxable year for federal tax purposes were limited to the period of residence, and the denominator of which is such individual's or trust's New York adjusted gross income for the entire taxable year. For purposes of the preceding sentence, New York adjusted gross income means New York adjusted gross income determined under article twenty-two of this chapter.