§ 611. New York taxable income of a resident individual. (a) General. The New York taxable income of a resident individual shall be his New York adjusted gross income less his New York deduction and New York exemptions, as determined under this part.

(b) Husband and wife.

(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:

(A) their tax shall be determined on their joint New York taxable income, or

(B) separate taxes may be determined on their separate New York taxable incomes if they both so elect.

(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.