Q21: Congenital malformations of cardiac septa

Codes under Q21 (Congenital malformations of cardiac septa). A ✓ marks a billable (fully specified) code; category codes without a ✓ are not billable on their own.

Code	Description	Billable
Q21.0	Ventricular septal defect	✓
Q21.1	Atrial septal defect	—
Q21.2	Atrioventricular septal defect	—
Q21.3	Tetralogy of Fallot	✓
Q21.4	Aortopulmonary septal defect	✓
Q21.8	Other congenital malformations of cardiac septa	✓
Q21.9	Congenital malformation of cardiac septum, unspecified	✓
Q21.10	Atrial septal defect, unspecified	✓
Q21.11	Secundum atrial septal defect	✓
Q21.12	Patent foramen ovale	✓
Q21.13	Coronary sinus atrial septal defect	✓
Q21.14	Superior sinus venosus atrial septal defect	✓
Q21.15	Inferior sinus venosus atrial septal defect	✓
Q21.16	Sinus venosus atrial septal defect, unspecified	✓
Q21.19	Other specified atrial septal defect	✓
Q21.20	Atrioventricular septal defect, unspecified as to partial or complete	✓
Q21.21	Partial atrioventricular septal defect	✓
Q21.22	Transitional atrioventricular septal defect	✓
Q21.23	Complete atrioventricular septal defect	✓

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Informational only, not coding or medical advice. Verify against the official ICD-10-CM (FY2026) and your payer's guidelines.

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