​The Centers for Medicare & Medicaid Services (CMS) require that all hospitals and critical access hospitals (CAH) provide the Medicare Outpatient Observation Notice (MOON) to beneficiaries in Original Medicare (fee-for-service) and Medicare Advantage enrollees who receive observation services as an outpatient for more than 24 hours.

This notice informs beneficiaries that they are outpatients receiving observation services. They are not inpatients of a hospital or CAH.

The hospital or CAH must issue the MOON no later than 36 hours after observation services as an outpatient begin.

This also applies to beneficiaries in the following circumstances:

• beneficiaries who are subsequently admitted as an inpatient prior to the required delivery of the MOON;
• beneficiaries for whom Medicare is either the primary or secondary payer.

Learn more

To access the MOON and completion instructions, please visit the CMS website.