The Medicare 72-Hour Rule (officially known as the 3-Day Payment Window) is one of the most confusing regulations for hospital billing departments. If you bill an outpatient service that falls within this window, Medicare will demand a refund.
What is the 3-Day Payment Window?
Medicare requires that all diagnostic services (and any therapeutically related non-diagnostic services) provided to a Medicare beneficiary by a hospital (or a wholly owned entity of the hospital) within 3 days prior to an inpatient admission MUST be bundled into the inpatient DRG payment.
Real-World Examples
- Example 1 (Diagnostic): A patient gets a chest X-ray and EKG at the hospital''s outpatient clinic on Monday. On Wednesday, the patient is admitted as an inpatient for pneumonia. The X-ray and EKG CANNOT be billed on a separate outpatient UB-04. They must be added to the inpatient claim.
- Example 2 (Non-Diagnostic, Unrelated): A patient gets physical therapy for a knee replacement on Tuesday. On Thursday, they suffer a massive heart attack and are admitted. Because the physical therapy is non-diagnostic and clinically unrelated to the heart attack admission, it CAN be billed separately as an outpatient service.
Condition Code 51
If you have an outpatient service that occurred within the 3-day window, but is clinically UNRELATED to the admission, you must append Condition Code 51 to the outpatient UB-04 claim to bypass the automated rejection.