24 CFR § 982.155 - Administrative fee reserve.
(a) The PHA must maintain an administrative fee reserve (formerly “operating reserve”) for the program. There is a single administrative fee reserve for the PHA program. The PHA must credit to the administrative fee reserve the total of:
(2) Interest earned on the administrative fee reserve.
(1) The PHA must use funds in the administrative fee reserve to pay program administrative expenses in excess of administrative fees paid by HUD for a PHA fiscal year. If funds in the administrative fee reserve are not needed to cover PHA administrative expenses (to the end of the last expiring funding increment under the consolidated ACC), the PHA may use these funds for other housing purposes permitted by State and local law. However, HUD may prohibit use of the funds for certain purposes.
(3) If the PHA has not adequately administered any Section 8 program, HUD may prohibit use of funds in the administrative fee reserve, and may direct the PHA to use funds in the reserve to improve administration of the program or to reimburse ineligible expenses.