Medical Provider

Medicare Outpatient Observation Notice (MOON)

When a Medicare beneficiary receives outpatient observation services from a hospital or critical access hospital (CAH) for more than 24 hours, he or she (or the beneficiary’s authorized representative) must receive a Medicare Outpatient Observation Notice (MOON). The written MOON and a verbal explanation of the notice must be delivered no later than 36 hours after services were initiated. The MOON is mandated by the Federal Notice of Observation Treatment and Implication for Care Eligibility Act (NOTICE Act), passed on Aug. 6, 2015.

Important notes:

  • The MOON may be delivered before a beneficiary receives 24 hours of observation services as an outpatient.
  • If the beneficiary is transferred, discharged or admitted, the MOON still must be delivered no later than 36 hours following initiation of observation services.
  • The start time of observation services is measured as the clock time observation services are initiated in accordance with a physician’s order.

Hospitals and CAHs must use one of the following Office of Management and Budget (OMB)-approved MOONs, which can be downloaded on the CMS website:

  • MOON_v508
  • MOON_Largeprint_v508
  • MOON_Spanish_v508
  • MOON_Spanish_Largeprint_v508

Instructions on how to fill out the MOON can be found here. Additional information about the MOON can be found in CMS MLN Matters Number 9935 at