ICD-10-CM · Chapter 17 · Q00-QA1
Q21 Congenital malformations of cardiac septa
Excludes 1 (cannot be coded together)
- acquired cardiac septal defect (I51.0)
Subcodes
Subcodes are listed below for reference. Detail pages are not available for chapters 11–22.
| Code | Description | Billable |
|---|---|---|
| Q21..0 | Ventricular septal defect | Yes |
| Q21..1 | Atrial septal defect | No |
| Q21..10 | Atrial septal defect, unspecified | Yes |
| Q21..11 | Secundum atrial septal defect | Yes |
| Q21..12 | Patent foramen ovale | Yes |
| Q21..13 | Coronary sinus atrial septal defect | Yes |
| Q21..14 | Superior sinus venosus atrial septal defect | Yes |
| Q21..15 | Inferior sinus venosus atrial septal defect | Yes |
| Q21..16 | Sinus venosus atrial septal defect, unspecified | Yes |
| Q21..19 | Other specified atrial septal defect | Yes |
| Q21..2 | Atrioventricular septal defect | No |
| Q21..20 | Atrioventricular septal defect, unspecified as to partial or complete | Yes |
| Q21..21 | Partial atrioventricular septal defect | Yes |
| Q21..22 | Transitional atrioventricular septal defect | Yes |
| Q21..23 | Complete atrioventricular septal defect | Yes |
| Q21..3 | Tetralogy of Fallot | Yes |
| Q21..4 | Aortopulmonary septal defect | Yes |
| Q21..8 | Other congenital malformations of cardiac septa | Yes |
| Q21..9 | Congenital malformation of cardiac septum, unspecified | Yes |
Last reviewed: September 2026