N.Y. Retire. & Soc. Sec. Law § 31-a

§ 31-a. Participation by school district public libraries. a. A\nschool district public library, by resolution legally adopted by its\nboard of trustees, may elect to become a participating employer in the\nretirement system, separate and distinct from the school district.\nAcceptance of the school district public library as a participating\nemployer in the retirement system shall be mandatory with the\ncomptroller.\n b. The officers and employees of such library shall be credited with\nsuch periods of prior service as shall be certified by the library for\nservice rendered to it, or its predecessor, or the state, or in any\nother capacity approved by such library and the comptroller. Service for\nsuch library after the date on which it commences to participate in the\nretirement system shall be considered as member service. An officer or\nemployee of such library who, as of the date he is so approved for\nmembership in the retirement system, is already a member thereof, shall\nnot have his total credit reduced by such approval. Any reserve held on\naccount of any such officer or employee in the pension accumulation fund\nshall be used as an offset against the deficiency contribution payable\nthereafter by such library on account of such officer or employee for\nany prior service credit and any such previous credit.\n