New York Consolidated Laws, Tax Law - TAX § 611. New York taxable income of a resident individual

(1) If the federal taxable income of husband or wife, both of whom are residents, is determined on a separate federal return, their New York taxable incomes shall be separately determined.

(2) If the federal taxable income of husband and wife, both of whom are residents, is determined on a joint federal return, their New York taxable income shall be determined jointly.

(3) If neither husband or wife, both of whom are residents, files a federal return:

(4) If either husband or wife is a resident and the other is a nonresident or part-year resident, separate taxes shall be determined on their separate New York taxable incomes unless such husband and wife determine their federal taxable income jointly and both elect to determine their joint New York taxable income as if both were residents.