FHIR Resource Explainer
Purpose
This skill explains FHIR resources and interoperability patterns in plain language. It is for people who work with health data but are not FHIR specialists: researchers, data managers, developers new to health standards, and clinical informaticians who need a grounded explanation before they plan an integration.
Where FHIR stands in 2026
- R5 is the current normative release (published March 2023). It is the release that new implementations should target.
- R6 is in ballot. As of August 2026, R6 has progressed through its full normative ballots (the second full ballot ran in mid-2026), with final publication targeted for 2027. It is not yet a published release, and production systems should not assume R6 features.
- US Core (current version 9.0.0, built on FHIR R4) is the US implementation guide that defines the minimum set of resources and profiles for US interoperability. It is updated regularly; check the current edition at hl7.org/fhir/us/core.
- IPS (International Patient Summary) is the standard for a minimal, shareable patient summary across borders.
- SMART on FHIR is the authorization and launch standard that lets apps connect to FHIR servers.
- FHIR Bulk Data Access (backport or R5) supports large-scale export of FHIR data, which matters for research datasets and analytics.
The European context: EHDS
The European Health Data Space (EHDS) Regulation was adopted in 2025. It establishes a framework for primary use of electronic health data and for secondary use of health data for research and innovation. Its implementation runs in stages: implementing acts for interoperability and secondary use are being developed from 2027, with main application milestones through 2029 and 2031. FHIR is the reference standard in the EHDS technical specifications, so teams planning European interoperability projects should build toward FHIR and monitor the EHDS implementing acts as they are published.
What a FHIR resource is
A FHIR resource is a self-contained, REST-friendly data structure with a stable identity. Examples include Patient, Observation, MedicationRequest, Encounter, Condition, and DocumentReference. Resources link to each other with references, and groups of resources are transported in Bundle resources.
The key idea for a beginner: FHIR standardizes the shape of the data and the way it is exchanged over HTTP (JSON or XML), so that different systems can share information without building one-off interfaces.
How to use this skill
Describe the resource and the context. The output gives you the plain-language meaning, the common fields, typical use cases, and safety notes. Use it when you need to explain a resource to a colleague, plan a data model, or decide whether a standard fits your use case. Then verify against the official specification at hl7.org/fhir for production work.
Common failure modes
- Version confusion: describing R4 features as if they were R5 or citing R6 as normative. The skill should always be explicit about releases.
- PHI in examples: using realistic-looking patient data in the explanation. Examples in this skill are synthetic and so should yours be.
- Overclaiming: implying that explaining a resource is the same as configuring a server. It is not; implementation guides and server behavior differ.
Integration with other skills
The FHIR Resource Explainer pairs with the Data Management skills: the Protocol-to-Data Dictionary defines variables, and FHIR explains how those variables map onto a standard exchange format. It also feeds the Healthcare AI Governance pack, where data interoperability is part of governance review.