Resolution: US Core will not add additional elements based on future USCDI requirements unless there is community consensus and a demonstration use extensive use in existing implementations.  Background:   USCDI v3  requirement Specimen Type Substance being sampled or tested. (e.g., nasopharyngeal swab, whole blood, serum, urine, wound swab) Other ONC “level 2” and Draft USCDI V4  data elements that are in the base FHIR Specimen Resource   Specimen Data Element ONC “level 2" Draft USCDI V4 Collection Date X   Source Site X X Condition X X Identifier X  X   No interest was expressed in searching for or supporting other elements in the resource during design calls. Rationale: The argument for adding Specimen.collected [x] is better Compliance with anticipated USCDI Regulations and data access. The argument against adding is lack of adoption, increased complexity, and development costs. US Core design was to provide the minimum requirements to meet USCDI v3 requirements or community consensus for elements that demonstrate extensive existing use in implementations.  The profiles provide a floor for standards development for specific use cases without burdening implementers with additional requirements.