Per CMS: 30.6.9 – Payment for Inpatient Hospital Visits – General, "C. Hospital Visits Same Day But by Different Physicians
In a hospital inpatient situation involving one physician covering for another, if physician A sees the patient in the morning and physician B, who is covering for A, sees the same patient in the evening, contractors do not pay physician B for the second visit. The hospital visit descriptors include the phrase per day meaning care for the day.
If the physicians are each responsible for a different aspect of the patients care, pay both visits if the physicians are in different specialties and the visits are billed with different diagnoses. There are circumstances where concurrent care may be billed by physicians of the same specialty."