42 CFR §435.1008

1. (a)This section implements sections 1137 and 1902(a)(46)(B) of the Act.
2. (b)Except as provided in paragraph (c) of this section, FFP is not available to a State for expenditures for medical assistance furnished to individuals unless the State has verified citizenship or immigration status in accordance with § 435.956.
3. (c)FFP is available to States for otherwise eligible individuals whose declaration of U.S. citizenship or satisfactory immigration status in accordance with section 1137(d) of the Act and § 435.406(c) has been verified in accordance with § 435.956, who are exempt from the requirements to verify citizenship under § 435.406(a)(1)(iii), or for whom benefits are provided during a reasonable opportunity period to verify citizenship, nationality, or satisfactory immigration status in accordance with section § 435.956(b), including the time period during which an appeal is pending if the State has elected the option under § 435.956(b)(3).