# same page, as API
GET autoicdapi.com/api/v1/reference/snomed-ct/3991000175109
GET autoicdapi.com/api/v1/translate?code=3991000175109&from=snomed&to=icd-10

Common questions

What is the SNOMED CT code for Failed encounter - left message with person?

Failed encounter - left message with person is coded as 3991000175109 in SNOMED CT.

What is SNOMED CT code 3991000175109?

3991000175109 is the SNOMED CT identifier for Failed encounter - left message with person. It is included in the most recent US Edition release of SNOMED CT.

What semantic tag does SNOMED CT 3991000175109 have?

3991000175109 is classified as a finding in SNOMED CT.

What is the ICD-10-CM mapping for 3991000175109?

3991000175109 maps to ICD-10-CM Z76.89.

What is the UMLS mapping for 3991000175109?

3991000175109 maps to UMLS C4039632.

SNOMED CT, plainly answered

What is SNOMED CT?

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.

How does SNOMED CT relate to ICD-10?

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.

Is the API free to use?

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.

How do I look up a SNOMED concept?

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.

How fresh is the SNOMED data?

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.

Do I need a SNOMED license?

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.