Section 424.15 - Requirements for inpatient CAH services(a) Medicare Part A pays for inpatient CAH services only if a physician certifies that the individual may reasonably be expected to be discharged or transferred to a hospital within 96 hours after admission to the CAH, and that the services are provided in accordance with § 412.3 of this chapter.(b) Certification begins with the order for inpatient admission. All certification requirements must be completed, signed, and documented in the medical record no later than 1 day before the date on which the claim for payment for the inpatient CAH service is submitted.78 FR 50970, Aug. 19, 2013, as amended at 79 FR 50359, Aug. 22, 2014