42 C.F.R. § 483.122 – FFP for NF services.

(a) Basic rule. Except as otherwise may be provided in an alternative disposition plan adopted under section 1919(e)(7)(E) of the Act, FFP is available in State expenditures for NF services provided to a Medicaid eligible individual subject to the requirements of this part only if the individual has been determined—
1. (1) To need NF care under § 483.116(a) or
2. (2) Not to need NF services but to need specialized services, meets the requirements of § 483.118(c)(1), and elects to stay in the NF.
(b) FFP for late reviews. When a preadmission screening has not been performed prior to admission or an annual review is not performed timely, in accordance with § 483.114(c), but either is performed at a later date, FFP is available only for services furnished after the screening or review has been performed, subject to the provisions of paragraph (a) of this section.