ICD-10-CM > Q00-QA0 > Q20-Q28 > Q21 > Q21.2 Q21.2 Atrioventricular septal defect Non-Billable/Non-Specific Applicable To Atrioventricular canal defectEndocardial cushion defectOstium primum atrial septal defect (type I) Codes Q21.20Atrioventricular septal defect, unspecified as to partial or completeQ21.21Partial atrioventricular septal defectQ21.22Transitional atrioventricular septal defectQ21.23Complete atrioventricular septal defect