The supervising physician must bill under the same group PIN as the other physician, and must have signed a form 855R reassigning his/her right to bill to the group. Coders should identify the supervising physician "in 2310B loop" and list his/her PIN in REF02 and the IC qualifier in REF01, CMS instructs.
When there's no "suite of rooms" in the office, then the supervising physician must actually be in the same room as the supervised provider, the transmittal clarifies.
CMS also inserted into the manual its new interpretation that providers cannot bill diagnostic tests on an incident-to basis, because these tests have their own benefit category. This interpretation has proved controversial because it means physicians in a group practice can't receive a share of reimbursement for diagnostic tests proportional to the amount of tests they order.