42 CFR 430.20 - Effective dates of State plans and plan amendments.
For purposes of FFP, the following rules apply:
(a) New plans. The effective date of a new plan -
(2) With respect to expenditures for medical assistance, may not be earlier than the first day on which the plan is in operation on a statewide basis.
(b) Plan amendment.
(1) For a plan amendment that provides additional services to individuals eligible under the approved plan, increases the payment amounts for services already included in the plan, or makes additional groups eligible for services provided under the approved plan, the effective date is determined in accordance with paragraph (a) of this section.