N.Y. Comp. Codes R. & Regs. tit. 2, § 338.2 – Termination of membership.

(a) The membership of those members who join or rejoin the retirement system on or after July 1, 1976 shall cease upon the occurrence of any one of the following conditions:
1. (1) when a member shall die;
2. (2) when a member shall retire; or
3. (3) when a member shall have withdrawn his or her accumulated contributions.
(b) In the case of members who are eligible to receive a refund of contributions prior to attaining age 62 and who are not eligible for vested benefits, membership shall terminate when seven years have elapsed since a member last engaged in public service.
(c) In the case of members who are not yet eligible to receive a refund of contributions prior to attaining age 62, membership shall terminate on the later of the two following dates:
1. (1) when a member attains age 62; or
2. (2) when seven years have elapsed since a member last engaged in public service.