Hospitalist Group both IM and FP

When you have a hospitalist group that is a mix of internal medicine physicians and family practice physicians and a patient is seen in critical care by an IM in the morning and an FP in the afternoon should the time still be combine as total cumluative icu time or should be billed separately based on their taxonomy codes? Should we be billing separately?
thank you

Combine them

they are serving the same role - as primary care and covering for each other so you cannot bill separately just because one is FP and one is IM