Question: Which modifiers should I use when reporting services and procedures under the teaching physician rules? Alabama Subscriber
Answer: You should use modifier -GC (This service has been performed in part by a resident under the direction of a teaching physician) if the oncologist wants to bill for an E/M service (for example, 99203, Office or other outpatient visit for the evaluation and management of a new patient ...) that a resident helped perform. Attaching this modifier lets the insurer know that you are reporting the E/M coding under the teaching physician rules and using Medicare's documentation guidelines.
Typically, Medicare requires teaching physicians to provide direct supervision over a resident's procedures and services. But in primary-care offices, teaching physicians can sometimes get paid when a resident performs a low-level E/M without the physician present in the exam room. When you report a code under Medicare's primary-care exception rule, make sure to attach modifier -GE (This service has been performed by a resident without the presence of a teaching physician under the primary-care exception) to let the payer know why your physician didn't directly supervise the office visit.
Remember that the primary-care exception does not apply to specialists, such as oncologists, but only to primary-care physicians like internists, who notify their local carrier in writing that they will be using the billing option.