N.Y.C. Admin. Code § 13-526: § 13-526 Contributions of the city and their use; expense fund.

a. The expense fund shall consist of such amounts as shall be appropriated, if any, by the employer on estimates submitted by the retirement board, to defray the expenses of the administration of this chapter, and such funds as may be secured pursuant to the provisions of subdivision b of section 13-518 of the code, subdivision k of section 13-570 of the code and subdivision b of section 13-582 of the code exclusive of the payment of pensions, of pensions-providing-for-increased-take-home-pay, of annuities, of retirement allowances, and of the other benefits provided for in this chapter.

b. The executive director shall develop procedures to ensure that the amounts expended during a fiscal year by the retirement system do not exceed the amounts paid into the expense fund pursuant to this section. Appropriate reporting will be made to the mayor's office of management and budget so as to provide the city of New York with the ability to conduct an independent analysis. Additionally, expenditures of the retirement system from the expense fund shall be subject to audit by the comptroller, who may recommend procedures designed to improve the accounting and expenditure controls.