42 CFR § 405.806 - Impact of reversal of contractor determinations on claims processing.
(a) Claims for services furnished to Medicare beneficiaries during a period in which the supplier billing privileges were not effective are rejected.
(b) If a supplier is determined not to have qualified for billing privileges in one period but qualified in another, Medicare contractors process claims for services furnished to beneficiaries during the period for which the supplier was Medicare-qualified. Subpart C of this part sets forth the requirements for the recovery of overpayments.
(c) If a revocation of a supplier's billing privileges is reversed upon appeal, the supplier's billing privileges are reinstated back to the date that the revocation became effective.
(d) If the denial of a supplier's billing privileges is reversed upon appeal and becomes binding, then the appeal decision establishes the date that the supplier's billing privileges become effective.