The providers would have to be a part of the same actual medical group........not just same specialty. Discharge services should only be billed by the Admitting provider.
As long as the two different physicians are a part of the same hospitalist group, (not just same specialty), then one may bill the admit, and the other may bill for discharge. The only instance that an entirely different provider (from a diff group) would be able to bill for discharge services would be if there is a signed transfer of care on file.
That being said......I am not sure that two different physicians would be able to (logistically) bill for an admit/dc same day code, even being a part of the same group, as it is techinically one encounter, one provider, TWO services. If you were to bill just under one provider, then you would be saying that the one provider performed BOTH services, when they only performed one aspect........we should only be billing under physicians that provided the actual services. Unless the same provider performed both the admit and discharge, they should not be billing for both....
Also, be careful when using the admit/dc same day codes that the services meet criteria (CMS requires patient be admitted at least 8 hrs on same calander date.....many commercial policies follow suit.) There also has to be seperate documentation for both encounters (an h&p and d/c summary need to be done seperately).
I also work for a hospitalist group. I do have physicians that try billing these codes without following the guidlines (typically will only document for the admit). In these cases, I would code just the admit CPT (like a 99221-99223).