What aspect is crucial when performing services in an outpatient clinic under "incident to" billing?

The aspect that is crucial when performing services in an outpatient clinic under "incident to" billing is that the physician must see the patient before the nurse practitioner (NP). This requirement is fundamental to the "incident to" billing rules established by Medicare. It ensures that the physician has established a patient-physician relationship and has developed a plan of care that the NP will follow. This initial visit is important because it provides a basis for the NP's subsequent services to be billed under the physician's National Provider Identifier (NPI), allowing for reimbursement at the full rate.

The intent behind this regulation is to maintain a certain level of oversight and coordination in patient care, ensuring that there is a physician's involvement in the patient's treatment plan. This is particularly relevant in outpatient settings where collaboration between different healthcare providers is essential to the quality of care provided.

While other aspects, such as whether the services are covered by the patient’s insurance or the nature of the services performed, may influence overall billing practices, the physician visiting the patient first is the cornerstone for "incident to" billing to be valid.