The Skilled Nursing Facility (SNF) 3-Day Rule is a Medicare policy that requires a beneficiary to have a qualifying hospital stay of at least three consecutive days (not counting the discharge day) before Medicare will cover SNF services. This policy is crucial for billing and reimbursement processes in SNFs, as it determines eligibility for Medicare Part A coverage for skilled nursing care.

Under this rule, the patient must be admitted to the hospital as an inpatient for three full days. It's important to note that time spent in the emergency department or in observation status does not count towards the 3-day rule. After meeting this requirement, Medicare Part A may cover the SNF stay if the patient is transferred to a Medicare-certified SNF and receives skilled care such as physical therapy, nursing services, or other types of rehabilitation services that are necessary for the treatment of their illness or injury.

Billing for SNF services under this rule requires meticulous documentation to ensure that the qualifying hospital stay meets the necessary criteria. SNFs must verify the hospital stay duration, the medical necessity of the inpatient stay, and that the services provided in the SNF are directly related to the condition treated during the hospital stay.

This policy has been subject to discussions and potential changes, including waivers under specific circumstances, such as for Accountable Care Organizations (ACOs) under certain Medicare models which may waive the requirement for a 3-day inpatient hospital stay prior to SNF admission.

For detailed information regarding the 3-Day Rule billing in your document, I recommend reviewing the specific sections related to Medicare billing guidelines, SNF coverage criteria, and any updates or exceptions to the rule that may apply.