42 CFR § 456.125
Time limits for admission review
June 11, 2020
Except as required under §456.127, the UR plan must provide that review of each beneficiary's admission to the hospital is conducted—
(a) Within one working day after admission, for an individual who is receiving Medicaid at that time; or
(b) Within one working day after the hospital is notified of the application for Medicaid, for an individual who applies while in the hospital.