Prolonge visits

There are two hospitalists that seen the patient on the same date. The first provider used the E/M code (99232). The second provider wants to use the prolonged visit code (99356).

The issue: Usually when two providers see the same patient on the same date and the providers are from the same specialty, Same group practice, the encounters are combined and only given to one of them. However, with prolonged visits it has usually been stated that the SAME provider that initiated the E/M service shall use the prolonged visit code(s) 99356 7 99357 (if warranted).

The confusion: According to Medicare; Same group, same specialty = one provider (single entity).

So going with the above logic, if Provider A sees the patient in the morning and submits an E/M and Provider B sees the patient in the evening (same date) and submits a prolonged service code; then it should be appropriate to use E/M code with a prolonged service code. Is this correct? If it is or not, can you please state your source as something I can refer to when posing this anwer.

Thank you in advance!