Documentation

Conceptual guides for the FHIR R4 standard. Each topic links to the full official documentation.

Foundation concepts

What FHIR is and how the spec is organized.

How resources work — identity, references, narrative, extensions.

Primitive and complex types used throughout the spec.

How resources point to one another.

Implementing FHIR

The HTTP-based API for reading and writing resources.

Search parameters, modifiers, and chaining.

Defined operations beyond basic CRUD.

Transaction, batch, and document bundles.

Conformance & terminology

Constraining resources for specific use cases.

Code systems, value sets, and concept maps.

Extending resources without breaking interoperability.