42 CFR § 423.642 - Notice of contract determination.
(a) When CMS makes a contract determination under § 423.641, it gives the PDP sponsor written notice.
(b) The notice specifies the—
(1) Reasons for the determination; and
(2) The Part D sponsor's right to request a hearing.
(c) CMS-initiated terminations—(1) General rule. Except as provided in (c)(2) of this section, CMS mails notice to the Part D plan sponsor 45 calendar days before the anticipated effective date of the termination.
(2) Exception. If a contract is terminated in accordance with § 423.509(b)(2)(i) of this part, CMS notifies the Part D plan sponsor of the date that it will terminate the Part D plan sponsor's contract.
(d) When CMS determines that it will not authorize a contract renewal, CMS mails the notice to the Part D sponsor by August 1 of the current contract year.