Rationale Since the LOINC is named in USCDI as the "Applicable Vocabulary Standard" and the binding is preferred, Other concepts can be used.  The purpose of US Core is to provide a common understanding and consistent interpretation of data elements. Still, with too many choices, it becomes difficult to determine which one to use and to ensure compatibility between systems. In such a scenario, having too many choices is the same as having no standard at all.   Background US Core Design principle is to make USCDI "Applicable Vocabulary Standard" a core  extensible binding (unless there is community agreement to choose another standard).  In this case the community feedback was to make the binding preferred since other standards like SNOMED CT are in wide use. SNOMED CT is a large, complex, and constantly evolving clinical terminology that contains over 350,000 concepts. It is better to select the relevant SNOMED CT concepts and create a binding that only includes those concepts.    Please note that we have used OpenAI's chatCPG to assist in answering this question. We review these responses, and the information provided is based on our experience, implementer feedback, and our design choices for US Core.