45 C.F.R. § 302.13
(b) Federal financial participation. Except where otherwise provided, Federal financial participation is available in the additional expenditures resulting from an amended provision of the State plan as of the first day of the calendar quarter in which an approvable amendment is submitted or the date on which the amended provision becomes effective in the State, whichever is later.
(Approved by the Office of Management and Budget under control number 0960-0253)
[40 FR 27159, June 26, 1975, as amended at 51 FR 37731, Oct. 24, 1986]