Currently, Medicare beneficiaries must have a three-day hospital stay to receive subsequent fully covered skilled nursing services. Hospitals admitting on an observation basis rather than inpatient has lead to very costly Medicare denials.
The American Health Care Association (AHCA) CEO has asked Centers for Medicare & Medicaid Services (CMS) to eliminate uncertainty on the Medicare three-day stay rule stating, “three days is three days”.
For more on this, see this article from @skilled_nursing.