N.Y.C. Admin. Code § 13-611: § 13-611 Retirement for service.

Any member who has performed duty for a period of ten years or upwards shall be relieved and dismissed from such force upon his or her own application, or by order of the commissioner, upon an examination by the medical examiners of such department, to be made at any time when so applied for or when so ordered, if a majority of such medical examiners certify that such member is permanently disabled, physically or mentally, so as to be unfit for duty. Such member so relieved and dismissed from such force shall be paid from such fund in monthly installments during his or her lifetime a sum not less than one-half of the annual salary or compensation of such member when so retired. A member who has performed duty on such force for a period of twenty-five years or upwards, whether continuous or rendered during different periods, upon the application of such member in writing, setting forth at what time, not less than thirty days subsequent to the execution and filing thereof, he or she desires to be retired, shall be relieved and dismissed from such force and service and shall be paid from such fund in monthly installments during his or her lifetime a sum not less than one-half of the annual salary or compensation of such member when so retired, provided that at the time so specified for his or her retirement, his or her term or tenure of office or employment shall not have terminated or been forfeited, and provided further that upon his or her request in writing the member shall be granted a leave of absence from the date of filing said application until the date the retirement becomes effective. No member shall be retired or granted a pension while there are charges of official misconduct pending against him or her. Pensions granted under this section shall be for the life of the pensioner, and shall not be revoked, repealed or diminished.