The CMS website says:
“For purposes of billing for E/M services, patients are identified as either new or established, depending on previous encounters with the provider.
New Patient: An individual who did not receive any professional services from the physician/non-physician practitioner (NPP) or another physician of the same specialty who belongs to the same group practice within the previous 3 years.
Established Patient: An individual who received professional services from the physician/NPP or another physician of the same specialty who belongs to the same group practice within the previous 3 years.” CMS.gov
A slide in the May 16, 2019, Professional Compliance Presentation at UCR School of Medicine in Palm Springs the same thing:
“New Patient is one who has not received any professional services from the physician or another physician in your specialty group, within the past three years. (99201 – 99205)
E/M services require 3 of 3 components be met or exceeded.
Established patient is one who has received professional services from the physician or another physician in your specialty group, within the past three years. (99211 – 99215)
E/M services require 2 of 3 components be met or exceeded.”
References / Source
Click to access eval-mgmt-serv-guide-ICN006764.pdf
May 16, 2019, Professional Compliance Presentation at UCR School of Medicine (Palm Springs location).