55221000

SNOMED CT is the world's most comprehensive clinical terminology, with around 350,000 active concepts covering diseases, findings, procedures, body structures, and substances. It is the recommended terminology for EHR problem lists in many countries.

SNOMED CT describes clinical meaning. ICD-10 (and ICD-10-CM) describes billing categories. The SNOMED to ICD-10-CM map (maintained by NLM) gives one or more ICD codes per SNOMED concept. We expose those mappings on each concept page and through the cross_references field on the API.

Browsing the directory is free for anyone with a browser. Programmatic access (the /api/v1/reference/snomed-ct/* endpoints) needs an API key. Free tier covers low-volume hobby use; paid tiers cover production traffic.

Either type the ID or a term into the search bar above, or call GET /api/v1/reference/snomed-ct/{concept_id}. Both paths return the same data: FSN, preferred term, semantic tag, synonyms, and cross-maps to ICD-10, ICD-11, UMLS, LOINC, and RxNorm where they exist.

We rebuild against the most recent US Edition release on each NLM publication cycle. Concept IDs and FSNs are stable across builds; new concepts and retirements are reflected within days of an upstream release.

Yes for any production use. SNOMED International controls licensing through national affiliates (NLM in the US). The free tier here is for evaluation. Paid plans assume the customer holds a valid affiliate license or is using an exempted use case.