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