42 CFR § 422.644 - Notice of contract determination.
(a) When CMS makes a contract determination under § 422.641, it gives the MA organization written notice.
(b) The notice specifies—
(1) Reasons for the determination; and
(2) The MA organization's right to request a hearing.
(c) CMS-initiated terminations—(1) General rule. Except as provided in paragraph (c)(2) of this section, CMS mails notice to the MA organization 45 calendar days before the anticipated effective date of the termination.
(2) Exception. If a contract is terminated in accordance with § 422.510(b)(2)(i) of this part, CMS notifies the MA organization of the date that it will terminate the MA organization's contract.
(d) When CMS determines that it will not authorize a contract renewal, CMS mails the notice to the MA organization by August 1 of the current contract year.