CodeSystem resource (FHIR R4)

CodeSystem is the FHIR R4 resource for the CodeSystem resource is used to declare the existence of and describe a code system or code system supplement and its key properties, and optionally define a part or all of its content.

Resource	CodeSystem
FHIR version	R4 (4.0.1)
Canonical URL	http://hl7.org/fhir/StructureDefinition/CodeSystem
Required elements	status (1..1), content (1..1)

Example

{
  "resourceType": "CodeSystem",
  "id": "codesystem-ede335988e390534b4295d701f6791f1",
  "status": "draft",
  "content": "not-present"
}

Generated by the Pidgeon engine: pidgeon generate CodeSystem --seed 20260722.

Validation context

strict pidgeon validate grades a CodeSystem instance against the base R4 structure definition: missing required elements raise REQUIRED_FIELD_MISSING and cardinality violations raise CARDINALITY_MIN or CARDINALITY_MAX.(REQUIRED_FIELD_MISSING)

This answer, in your terminal

pidgeon lookup CodeSystem

Wire it into your AI agent:

claude mcp add pidgeon -- npx -y @pidgeonhealth/mcp

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