In the hospital: admitted or under observation, the three-day rule, and the first week home

Ask on day one: inpatient or observation?

A person can sleep in a hospital bed for three nights and still be an outpatient. Observation is a hospital outpatient service used while the doctor decides whether to admit. It looks and feels the same as being admitted, and it is billed differently. Ask the nurse or the case manager every day: is she inpatient or observation? The answer can change.

The MOON notice

If someone on Medicare is under observation for more than 24 hours, the hospital must give them a written Medicare Outpatient Observation Notice, called the MOON, and explain it. It tells you they are an outpatient, what that may cost, and that it affects care after discharge. If you have not seen one and they have been there more than a day, ask for it.

Why it matters: the three-day rule

Under Original Medicare, Part A pays for short-term rehab in a skilled nursing home only after a qualifying inpatient hospital stay of at least three days in a row, counting the day of admission but not the day of discharge, with the move to the nursing home generally within 30 days. Observation days and emergency room time do not count. So a person who spent four days under observation and then goes to rehab can be billed for the whole rehab stay. Some Medicare Advantage plans and some accountable care arrangements waive the three-day rule; ask the plan.

The right to appeal a status change

Since February 14, 2025, a Medicare patient who was admitted as an inpatient and then switched to outpatient observation during the stay can ask for a fast appeal. The hospital must give a Medicare Change of Status Notice; it explains how. Appeal while still in the hospital if you can. The reviewers usually decide within about two days. If the appeal wins, the stay counts as inpatient, which can restore rehab coverage.

Questions for the case manager

• Is this stay inpatient or observation, and has it changed since admission?
• If observation, has the MOON been given, and can the doctor reconsider admission?
• If rehab is likely, will there be three inpatient days before discharge?
• What plan is the patient on: Original Medicare, a supplement, or Medicare Advantage? Does the plan need to approve rehab first?
• Who is our discharge planner, and how do we reach them directly?

The first week home

The month after a hospital stay is when people most often end up back in one, and a lot of that is preventable. Our coming-home article has the 30-day plan; this is the first seven days.

• Day 1: rebuild the medicine list from the discharge papers, bag the old bottles, and set up the pill box. Confirm which pharmacy has the new prescriptions.
• Day 1: clear the path to the bathroom, set up a first-floor bed if needed, and make sure the equipment ordered actually arrived.
• Day 2 or 3: the home health nurse's first visit, if ordered. Be there. Ask which signs mean call the doctor and which mean 911, and write them on the fridge.
• Within the week: the follow-up doctor visit. If it is not booked, book it. Bring the discharge summary and the medicine list.
• All week: someone checks in every day, in person or by phone. Ask about eating, drinking, bathroom, sleep, pain, breathing, and confusion.
• By day 7: decide whether the plan is working. If it is not, call the doctor and the home health agency, not the emergency room, unless it is an emergency.

Your rights before discharge

Medicare patients get a written notice of their discharge rights and can ask for a fast appeal if discharge feels too soon; the number is on the notice. You can ask for a family meeting, ask which facilities have accepted your person, and choose among them. A discharge is not safe just because the bed is needed.