Recognized Coordinating Entity (RCE) Implementation Guide
1.0.8 - Release 1 United States of America flag


Full Implementation Guide

The entire implementation guide (including the HTML files, definitions, validation information, etc.) may be downloaded here.

In addition there are format specific definitions files.


All the examples that are used in this Implementation Guide available for download:

Cross Version Analysis

This is an R4 IG. None of the features it uses are changed in R4B, so it can be used as is with R4B systems. Packages for both R4 ( and R4B ( are available.

Dependency Table

Package hl7.fhir.uv.extensions.r4#5.1.0

This IG defines the global extensions - the ones defined for everyone. These extensions are always in scope wherever FHIR is being used (built Sat, Apr 27, 2024 18:39+1000+10:00)


The US Core Implementation Guide is based on FHIR Version R4 and defines the minimum conformance requirements for accessing patient data. The Argonaut pilot implementations, ONC 2015 Edition Common Clinical Data Set (CCDS), and ONC U.S. Core Data for Interoperability (USCDI) v1 provided the requirements for this guide. The prior Argonaut search and vocabulary requirements, based on FHIR DSTU2, are updated in this guide to support FHIR Version R4. This guide was used as the basis for further testing and guidance by the Argonaut Project Team to provide additional content and guidance specific to Data Query Access for purpose of ONC Certification testing. These profiles are the foundation for future US Realm FHIR implementation guides. In addition to Argonaut, they are used by DAF-Research, QI-Core, and CIMI. Under the guidance of HL7 and the HL7 US Realm Steering Committee, the content will expand in future versions to meet the needs specific to the US Realm. These requirements were originally developed, balloted, and published in FHIR DSTU2 as part of the Office of the National Coordinator for Health Information Technology (ONC) sponsored Data Access Framework (DAF) project. For more information on how DAF became US Core see the US Core change notes. (built Mon, Jun 28, 2021 19:09+0000+00:00)

Package hl7.fhir.uv.extensions.r4#1.0.0

This IG defines the global extensions - the ones defined for everyone. These extensions are always in scope wherever FHIR is being used (built Sun, Mar 26, 2023 08:46+1100+11:00)


The Sequoia Project Healthcare Directory implementation guide (IG) is an abstract IG designed to accommodate the underlying needs of Sequoia Project initiatives such as Carequality (CQ) and eHealthExchange (eHx). This implementation guide is not intended to be implemented directly. Rather, it is where base profiles, values sets, code systems, and other such artifacts that are common all initiatives are defined, and they are intended to be further constrained in specific implementable IGs for those initiatives.

This IG is based on US Core, and uses uses the same [conformance guidance] as that IG, including the definition of must-support.

Much of the prose pages in the table of contents in this implementation guide is was copied directly from the pre-STU3 version of the IG, and contains information that is no longer applicable to FHIR R4 or this IGs role as an abstract base IG. Please take it with a grain of salt, so to speak. Those pages will be updated in future releases. (built Tue, May 21, 2024 12:38-0400-04:00)

Globals Table

There are no Global profiles defined

IP Statements

This publication includes IP covered under the following statements.