Q21 is the ICD-10 code for Congenital malformations of cardiac septa. It is a three-character category divided into 7 subcodes; use the subcode whenever the record supports that level of detail. It belongs to the block Q20–Q28 (Congenital malformations of the circulatory system) in Chapter XVII, Congenital malformations, deformations and chromosomal abnormalities.
- Code type
- Category (3 characters)
- Chapter
- XVII · Q00–Q99
- Classification
- WHO ICD-10, 2019 version
What Q21 excludes
Conditions that look similar but belong under another code.
- acquired cardiac septal defect I51.0
Subcodes of Q21
Q21 in national editions
Countries report with their own edition of ICD-10. Most keep the WHO code and add more specific codes beneath it.
DQ21Medfødte misdannelser af hjerteskillevæg
Q21Synnynnäiset sydämen väliseinien epämuodostumat
Q21Angeborene Fehlbildungen der Herzsepten
Q21Malformations congénitales des cloisons cardiaques
Q21congenitale misvormingen van hartsepta
Based on the World Health Organization’s International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10), 2019 version, and the national editions published by each country’s health authority. This page is a reference, not coding advice; follow your national coding rules when you report.
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