What is the primary distinction between "New Patient" and "Established Patient" E/M codes?

The primary distinction between "New Patient" and "Established Patient" E/M codes hinges on the timeframe since the patient last had a visit with a provider. New patient codes are designed for patients who have not been seen by the provider or another provider in the same group practice within the last three years. This reflects a lack of prior relationship and the need for a more comprehensive assessment, which is typically required during the initial consultation.

Option B accurately captures this definition, indicating that new patient codes are applicable for patients who haven't been seen by the provider in the last three years, thereby emphasizing the importance of establishing a clinical history and rapport during the first visit.

Other options do not correctly define new or established patient classifications; for instance, saying that new patient codes are for those seen within the last year is incorrect, as the period is longer. Established patient codes are not meant for first-time visits, and the definition of established patients does not depend on the timing of their last visit being within a month but rather focuses on whether they've had prior visits within the last three years.