N.Y. Comp. Codes R. & Regs. tit. 2 § 335.2
As applied to members of the New York State Employees' Retirement System and the New York State Policemen's and Firemen's Retirement System and used in sections 61, 361, 501 and 601 of the Retirement and Social Security Law, the terms dependent parent, dependent father and dependent mother shall mean, respectively, a parent, father and mother who have been claimed as a dependent on the deceased member's Federal income tax return for the taxable year immediately preceding the year of the member's death. However, an individual shall not be considered either a dependent parent, dependent father or a dependent mother where the Internal Revenue Service has disallowed the deceased member's claim that he or she is a dependent parent.
N.Y. Comp. Codes R. & Regs. Tit. 2 § 335.2