US Core 7.0 adds "location" as a MustSupport element to Immunization. Conceptually, this might be helpful if indicating the location at which an immunization was administered. However, the Immunization Community has been and continues to function based on the need to understand if the submitted of an immunization administration record is the primary source (meaning "it was given here") or not, and addressing "source" not by location, but using a specific PHIN-VADS value set Source of Information (https://phinvads.cdc.gov/vads/ViewValueSetConcept.action?id=54C35E6E-6D6B-11EB-9CAB-00505693340B). It is part of existing and active HL7 v2 communication between EHRs (immunization administration sites) and public health immunization registries known as Immunization Information Systems (IIS). The information does not specify a specific location which, in current US Core terms would be an address, the value set specifies information critical to understanding its reliability, specifically, a value set with the following meaning.  US Core should align with common practice and include instead [Immunization.reportOrigin|reportOrigin] and bind to the value set referenced above and displayed below - that is the current in use practice.  Location does not have sufficient meaning to support the IIS community.