From Medicare.gov

Medical or surgical care you get from a hospital when your doctor hasn’t written an order to admit you to the hospital as an inpatient. Outpatient hospital care may include emergency department services, observation services, outpatient surgery, lab tests, or X-rays. Your care may be considered outpatient hospital care even if you spend the night at the hospital.

RaphaelFrom Medicare.gov Medical or surgical care you get from a hospital when your doctor hasn't written an order to admit you to the hospital as an inpatient. Outpatient hospital care may include emergency department services, observation services, outpatient surgery, lab tests, or X-rays. Your care may be considered outpatient hospital...Making Senior Health Simple« Back to Glossary Index