CodeSystem

Overview

CodeSystem resources provide medical terminology lookup. Data is country-aware — the system returns codes appropriate for the user's organization country.

Dataset	Country	Count	National Org
ICD-10 diagnosis codes	ID	267 flat resources	Indonesian National
ICD-10 chapters + codes	SK	22 chapters, 2,351 codes	Slovak National
ICD-9-CM procedure codes	ID	257 codes	Indonesian National
SNOMED CT specialties	SK	27 specialties	Slovak National

ICD-10 Diagnosis Search

GET /CodeSystem/icd10/$search?q={query}&limit={limit}&offset={offset}&country={code}&org_id={orgId}

Parameters

Parameter	Type	Description
`q`	string	Search query (searches code + display text)
`limit`	number	Page size (default: 20)
`offset`	number	Pagination offset
`country`	string	Country code (`SK` or `ID`)
`org_id`	string	Alternative: resolve country from org

Response

[
  {
    "code": "E11.9",
    "display": "Type 2 diabetes mellitus without complications",
    "system": "http://hl7.org/fhir/sid/icd-10"
  }
]

ICD-10 Chapters

GET /CodeSystem/icd10/$chapters

Returns chapter groupings (e.g., "Chapter IV: Endocrine diseases").

ICD-10 Tree

GET /CodeSystem/icd10/$tree?chapter={chapterId}

Returns hierarchical tree structure for a chapter.

ICD-9-CM Procedure Search

GET /CodeSystem/icd9/$search?q={query}&limit={limit}&offset={offset}&category={cat}

ICD-9-CM Categories

GET /CodeSystem/icd9/$categories

Returns procedure categories with counts.

SNOMED CT Specialties

GET /CodeSystem/specialties/$list

Returns practice specialties used for organization categorization.

Code Lookup

FHIR $lookup operation:

GET /CodeSystem/$lookup?system={system}&code={code}

Parameters

Parameter	Type	Description
`system`	string	Code system URI (e.g., `http://hl7.org/fhir/sid/icd-10`)
`code`	string	Code to look up
`version`	string	Optional version