In the 3 mos I have been with this IM group, each physician has billed a 99220/99217 on a patient that they designated/admitted to observation on one day and actually discharged on the next day. I have had several insurance companies deny these charges due to invalid Place Of Service. This isn't my first pony ride, but apparently I'm missing something! What is the Place of Service that should be billed with these procedure codes?