C0018816
Congenital septal defect of heart
Concept
CUIC0018816
PreferredCongenital septal defect of heart
Cross-maps
SNOMED396351009
SNOMED59494005
SNOMED8352002
ICD-10MTHU006735
ICD-10MTHU033417
ICD-10Q21
ICD-10Q21.9
ICD-11LA8Z
Source vocabularies
Atoms not loaded for this concept.
# same page, as API
GET autoicdapi.com/api/v1/reference/umls/C0018816
GET autoicdapi.com/api/v1/translate?code=C0018816&from=umls&to=snomed-ct
Common questions
What is the UMLS CUI for Congenital septal defect of heart?
Congenital septal defect of heart is coded as C0018816 in UMLS.
What is UMLS code C0018816?
C0018816 is the UMLS identifier for Congenital septal defect of heart. It is included in the current NLM UMLS Metathesaurus release.
What is the ICD-10-CM mapping for C0018816?
C0018816 maps to 4 ICD-10-CM codes (MTHU006735, MTHU033417, Q21, Q21.9).
What is the ICD-11 mapping for C0018816?
C0018816 maps to ICD-11 LA8Z.
UMLS, plainly answered
What is UMLS?
The Unified Medical Language System is the NLM's meta-terminology that unifies SNOMED CT, ICD-10, ICD-11, RxNorm, LOINC, MeSH, and around 200 other source vocabularies under a single concept identifier (CUI). One UMLS CUI can group dozens of synonymous codes from different terminologies.
What is a CUI and why does it matter?
A CUI is a stable identifier (like C0011860) that points at a single clinical idea regardless of how that idea is encoded in any specific vocabulary. CUIs are the most reliable way to bridge between terminologies when you need to compare or merge data from multiple sources.
How does UMLS help with cross-mapping?
Every UMLS concept page lists the codes it groups together. That gives you a free crosswalk: a SNOMED concept and an ICD-10 code that share a CUI describe the same clinical idea. Our cross_references API returns these groupings inline.
Is the API free to use?
Browsing the directory is free. Programmatic /api/v1/reference/umls/* access needs an API key. Production volume requires a paid tier.
How fresh is the UMLS data?
We track NLM's twice-yearly releases (May AB and November AB). Each release brings new concepts, retirements, and atom updates from the source vocabularies, and our index reflects them within the same week.
Do I need a UMLS license?
Yes. The UMLS Metathesaurus License Agreement is free but requires an NLM UTS account. Customers in production need their own license. Free-tier evaluation use is permitted under the standard terms.