Once per physician/same specialty
Once per hospital stay, per physician (or other physicians in the same specialty, same group).
AND -- this rule applies ONLY to Medicare
If Dr A, a Cardiologist from Practice A, admits patient on 7-6-11; Dr A would use the 99221-99223 code as documented, with -AI modifier (to signify admitting physician)
If Dr B, a Neurologist from Practice A (same practice as Dr A but different specialty), also saw patient on 7-6-11, Dr B would use 99221-99223 code as documented but WITHOUT the -AI modifier. (IF patient has commercial insurance, Dr B would probably be using a consultation code.)
If Dr C, a Dermatologist from Practice A (same practice as Drs A & B, but another different specialty), then saw the patient on 7-7-11, Dr C would also use 99211-99223 (without the modifier) - and only if the patient was on Medicare.
I know this is confusing ... it would have been SOOOOo much easier if Medicare had simply adjusted their pay scale to equalize the pay for consults and admissions or new patient visits.
Hope that helps.
F Tessa Bartels, CPC, CEMC