What is the 2 Midnight Rule? What does it mean for your organization? How does it affect the amount Medicare patient’s pay out of pocket? How does the 2 Midnight Rule affect reimbursement from both inpatient and outpatient perspectives? The 2 Midnight Rule establishes guidelines as to whether or not a physician should admit a patient from outpatient to inpatient. The general rule is if the patient, based upon medical necessity, is expected to require care that will span at least 2 midnights, the patient should be admitted as inpatient, and therefore reimbursable under Medicare Part A. In determining the 2 midnights, all care including outpatient is used in the determination. However, in terms of reimbursement, outpatient is reimbursed via Medicare Part B provisions and inpatient is reimbursed via Medicare Part A provisions.