42 C.F.R. § 433.120
Procedures for reduction of FFP after reapproval review
(a) If CMS determines after the reapproval review that the system no longer meets the conditions for reapproval in § 433.119, CMS may reduce FFP for certain expenditures for system operations.
(b) CMS may reduce FFP from 75 percent to 50 percent for expenditures related to the operations of non-compliant functionality or system components.