34 C.F.R. § 222.74
(b) For applicant LEAs described in § 222.64(a)(2)(ii) and (a)(3)(ii), to identify the one or three generally comparable LEAs, the Secretary uses the following procedures:
(3) The LEA may then select as its generally comparable LEAs, for purposes of section 8003(b)(2) only, one or three LEAs from the list that are closest to it in size as determined by total ADA (i.e., the next one larger or the next one smaller, or the next three larger LEAs, the next three smaller, the next two larger and the next one smaller, or the next one larger and the next two smaller).
(Authority: 20 U.S.C. 7703(b)(2))