24 C.F.R. § 984.105 – Minimum program size.

(a) FSS program size—(1) Minimum program size requirement. A PHA must operate an FSS program of the minimum program size determined in accordance with paragraph (b) of this section.
(2) Exceptions to program operation requirement or to operate a smaller mandatory program. Paragraph (c) of this section states when HUD may grant an exception to the program operation requirement, and paragraph (d) of this section states when an exception may be granted to operate a program that is smaller than the minimum program size.
(3) Option to operate larger FSS program. A PHA may choose to operate an FSS program larger than the minimum program size.
(b) How to determine FSS minimum program size—(1) General requirement. Each PHA that was required to administer an FSS program on May 24, 2018 (enactment date of the Economic Growth, Regulatory Relief, and Consumer Protection Act), shall continue to operate such program for, at a minimum, the total number of families the PHA was required by statute to serve as of May 24, 2018, subject only to the availability of sufficient amounts for housing assistance under appropriations acts and the provisions of paragraph (b)(2) of this section.
(2) Reduction of minimum program size. The minimum program size for a PHA's FSS program is reduced by one slot for each family from any rental assistance program (public housing or Section 8, including multifamily assisted housing) for which the PHA administers FSS under this section and that graduates from the FSS program by fulfilling its FSS CoP on or after October 21, 1998. If an FSS slot is vacated by a family that has not completed its FSS CoP obligations, the slot must be filled by a replacement family which has been selected in accordance with the FSS family selection procedures set forth in § 984.203.
(c) Exception to program operation.
(1) Upon approval by HUD, a PHA will not be required to carry out an FSS program if the PHA provides to HUD a certification, as defined in § 984.103, that the operation of such an FSS program is not feasible because of local circumstances, which may include, but are not limited to, the following:
1. (i) Lack of supportive services accessible to eligible families, including insufficient availability of resources for programs under title I of the Workforce Innovation and Opportunity Act (29 U.S.C. 3111 et seq.);
2. (ii) Lack of funding for reasonable administrative costs;
3. (iii) Lack of cooperation by other units of State or local government; or,
4. (iv) Lack of interest in participating in the FSS program on the part of eligible families.
(2) A program operation exception will not be granted if HUD determines that local circumstances do not preclude the PHA from effectively operating an FSS program that is smaller than the minimum program size.
(d) Exception to operate a smaller mandatory program. Upon approval by HUD in its full discretion, a PHA may be permitted to operate an FSS program that is smaller than the minimum program size if the PHA requests an exception and provides to HUD a certification, as defined in § 984.103, that the operation of an FSS program of the minimum program size is not feasible because of local circumstances, which may include, but are not limited to:
(1) Decrease in or lack of supportive services available to eligible families, including insufficient availability of resources for programs under title I of the Workforce Innovation and Opportunity Act (29 U.S.C. 3111 et seq.);
(2) Decrease in or lack of funding for reasonable administrative costs;
(3) Decrease in or lack of cooperation by other units of State or local government; or
(4) Decrease in or lack of interest in participating in the FSS program on the part of eligible families.
(e) Expiration of exception. A full or partial exception to the FSS minimum program size requirement (approved by HUD in accordance with paragraph (c) or (d) of this section) expires five (5) years from the date of HUD approval of the exception. If circumstances change and a HUD-approved exception is no longer needed, the PHA is not required to effectuate the exception for the full term of the exception. If a PHA seeks to continue an exception after its expiration, the PHA must submit a new request and certification to HUD for consideration.
(f) Review of certification records. HUD reserves the right to examine, during its management review of the PHA, or at any time, the documentation and data that a PHA relied on in certifying to the unfeasibility of its establishing and operating an FSS program, or of operating one of less than minimum program size.