Background: The DSTU2 to R4 Conversion Page is intended to ensure a smoother upgrade path between versions. However, it has not been updated since ver 3.1.1. We currently provide a detailed change log for each version which is published along with the version history. Since version 3.1.1, The IG Publisher also create a QA artifact that compares the differences between versions.. For example between the ballot and Version 4.0.0 is published here: http://hl7.org/fhir/us/core/comparison-v3.2.0/index.html . In addition, we have had discussions with the Inferno team and ONC regarding identifying changes that are corrections to prior US Core versions in order to helps both implementers and testing authority for certification. Reasoning: There is a need for testers, certification candidates and implementers to understand the changes between versions. In addition to the change logs and QA artifacts, recasting this page as a more general guide to IG changes and providing a more complete picture of these changes on this page may better assist implementers in the transitions between versions.   Proposed Changes: 1. Update the Comparison of between version to include comparisons between all versions since Argonaut DSTU (e.g.: for changes between this version -5.0.0 and DSTU2, 3.1.1, 4.0.0 ) *note we are omitting FHIR R3 versions 2. Rename "DSTU2 to R4 Conversion" to "Changes Between US Core Versions" 3. Update Page to Reflect the broader focus , but maintain emphasis on DSTU2 to R4 Conversion Reference and describe the purpose and function of History page including the version summaries and Change Logs Reference and describe the purpose and function Comparison QA artifacts Update the table that summarizes the different profiles and resource types between DSTU2 and R4 to indicate the version when new artifacts added. Document how to identify corrections as a "patch" to a prior version for the purpose of ONC Certification.