New York Codes, Rules and Regulations
Title 21 - Miscellaneous
Chapter LVIII - New York State Teachers' Retirement System
Part 5009 - Vesting (deferred Retirement)
Section 5009.4 - Rights of a member with a date of membership on or after September 1, 1983 but before January 1, 2010, who has vested

(a) A member who has five or more years of credited service on termination of employment shall be automatically vested and shall be entitled to a deferred vested benefit at retirement age in accordance with the provisions of sections 603 and 604 of the Retirement and Social Security Law.

(b) In no event shall the vested retirement allowance payable without optional modification be less than the actuarial equivalent of the total which results from the member's contributions accumulated with interest at five percent per annum compounded annually to the date of retirement.