This page is part of the FHIR Specification (v5.0.0: R5 - STU). This is the current published version. For a full list of available versions, see the Directory of published versions . Page versions: R5 R4B R4 R3

Work Group FHIR Infrastructure

Standards Status: Informative

2.0 Foundation Module

The Foundation Module is responsible for the overall infrastructure of the FHIR specification. Every implementer works with the content in the foundation module whichever way they use FHIR.

The Foundation Module maintains most of the basic documentation for the FHIR specification. In addition, the Foundation Module includes the following resources:

2.0.1 Relationships with other modules

• All the other modules depend on the foundation module
• The Exchange module builds on the foundation model by defining the recognized methods for exchange of resources
• The Terminology module provides the formal basis for using Concepts defined in Code Systems in the definitions
• The Conformance module provides the basis for extending the foundation for national and local use
• The Security & Privacy provides the linking framework to external standards for security and privacy
• The Implementation Support module builds on the foundation to provide testing and reference implementations

2.0.2 Developmental Roadmap

Several components of the foundation module have now reached normative status. The focus over the next 18-24 months as the 6th release of FHIR is prepared is to focus on some of the non-normative elements and move them towards normative status, such as Questionnaire, List, DocumentReference and Subscription. Exactly which resources will be candidates for normative release will be driven, in part, by the degree of implementation - and whether that implementation is communicated back to HL7.

These resources are stable, normative, and widely used. No additional scope or features have been proposed:

• Resource
• DomainResource
• Binary
• Bundle
• Parameters
• OperationOutcome

These resources have been widely used, and are considered stable, but some new features are still in trial:

• Questionnaire
• QuestionnaireResponse
• List
• DocumentReference (note that here have been significant redesigns in this version).

These resources have been used, and the use led to a significant redesign that is undergoing trial use:

• Subscription:
• SubscriptionStatus:
• SubscriptionTopic:

These resources have not been widely used:

• Basic (note that no additional requirements have been identified since R2)
• MessageHeader