ICD-10-CM > Q00-QA0 > Q20-Q28 > Q21 > Q21.8 Q21.8 Other congenital malformations of cardiac septa Billable/Specific Copy Code Copy Description Applicable To Eisenmenger's defectPentalogy of Fallot Code Also , if applicable:Eisenmenger's complex (I27.83)Eisenmenger's syndrome (I27.83)