Hospitialist Medicine

We see patients in the hospital setting only. Lately we are having to change our patient's status from in patient to observation, observation to in patient and had a new one yesterday observation admit 99220 to out patient day two.

In CMS guidelines it says the physician determines the status of the admission but that is not true, Case Management does.

The patient was in an ambulatory surgery center. Is the following coding correct?

99220 day one
99213 day two
99213 day three
and what do we do on day four with an outpatient to discharge them?

In 8 years of working I have not encountered this and am really not sure how to bill out our visits.