Medicare Observation Status vs. Inpatient Admission
Short answer
Staying overnight in a hospital does not automatically make you an inpatient. Under Original Medicare, you are generally an inpatient only after a doctor or other authorized practitioner formally admits you under an inpatient admission order. Observation services are outpatient services, even when you spend the night in a hospital bed.
Why hospital status matters
Hospital status can affect whether Part A or Part B pays for hospital services, what you owe, and whether hospital days count toward the ordinary qualifying inpatient-stay requirement for subsequent skilled nursing facility coverage. Because the financial and post-hospital consequences can be significant, ask the hospital whether you are inpatient or outpatient whenever the status is unclear.
The Medicare Outpatient Observation Notice
If you receive outpatient observation services for more than 24 hours in a hospital or critical access hospital, the hospital generally must give you the Medicare Outpatient Observation Notice, or MOON. The notice explains that you are an outpatient receiving observation services, why that status applies, and how it may affect your hospital and post-hospital costs.
Observation and skilled nursing facility coverage
Under the ordinary Original Medicare skilled nursing facility rule, observation days generally do not count toward the required three consecutive inpatient hospital days. A person can therefore spend several nights at a hospital yet fail to satisfy the ordinary SNF qualifying-stay rule if those days were outpatient observation rather than inpatient admission. Certain waivers or other exceptions can change the ordinary rule.
If the hospital changes your status
Medicare provides appeal rights in certain situations when a hospital changes an inpatient admission to outpatient observation status. Read any written notice promptly because expedited review deadlines can be short. Keep the admission orders, MOON or other notices, discharge paperwork, and bills.
Medicare Advantage
Medicare Advantage plans must cover Medicare-covered hospital services, but plan authorization, network and cost-sharing rules can differ. Ask your plan how it treats the hospital stay and any post-acute care before relying on an Original Medicare cost estimate.