N.Y.C. Admin. Code § 13-631: § 13-631 Preservation of retirement and civil service rights; members of police and fire departments holding civil defense positions.

a. Notwithstanding any other provision of this code or any other law, in any case where any member of any pension or retirement system maintained under chapter two of this title or subchapter one or two of chapter three of this title, is granted a leave of absence from any position held by such person while such a member, and thereafter and during such leave of absence, is appointed to any position in the office of civil defense of the city, or to any position which has been designated, with the approval of the city civil service commission, as an emergency defense position, such member, in the same manner and to the same extent as if his or her service in such new position were service in the position from which such leave of absence was granted, and were service at the salary of such latter position, shall retain all of his or her rights, privileges and obligations as a member of such retirement system, and shall be entitled to service credit in such system for the period of his or her service in such new position.

b. Any member of the police force of the police department of the city, or of the uniformed force of the fire department of the city, who, while on leave of absence from any position in the competitive class of the civil service in either such department, holds another position in the office of civil defense of the city, or another position which has been designated, with the approval of the city civil service commission, as an emergency defense position, shall, except as to payment of compensation suspended by reason of such leave of absence, retain all of the rights, privileges and status of the position from which such leave of absence was granted, and shall be credited with service in the same manner as if service in such position in the office of civil defense or emergency defense position were service in such position from which a leave of absence was granted, and were service at the salary of such latter position.