Q21.8 Other congenital malformations of cardiac septa

Billable ICD-10-CM code, FY2026. Exempt from present-on-admission (POA) reporting.

Applicable to

• Eisenmenger's defect
• Pentalogy of Fallot

Code also

• , if applicable:
• Eisenmenger's complex (I27.83)
• Eisenmenger's syndrome (I27.83)

Applies from Q21 Congenital malformations of cardiac septa

Excludes1 (never code together)

• acquired cardiac septal defect (I51.0)

MS-DRG index

Defines the logic of DRG(s) 306-307 in MDC 05.

Approximate ICD-9-CM (GEMs)

• 745.8 Other bulbus cordis anomalies and anomalies of cardiac septal closure (approximate)

Code annotations containing back-references to Q21.8

Back-references to Q21.8

• Code Also: I27.83 Eisenmenger's syndrome ("Eisenmenger's defect (Q21.8)")

Back-references to Q21

• Code Also: I27.21 Secondary pulmonary arterial hypertension ("congenital heart disease (Q20-Q28)")
• Type 2 Excludes: P29 Cardiovascular disorders originating in the perinatal period ("congenital malformations of the circulatory system (Q20-Q28)")
• Code Also: Q87.85 MED13L syndrome ("congenital malformations of cardiac septa (Q21.-)")
• Code Also: Z71.87 Encounter for pediatric-to-adult transition counseling ("congenital malformations of the circulatory system (Q20-Q28)")

Diagnosis Index entries for Q21.8

• Anomaly, anomalous (congenital) (unspecified type) › cardiac › septal closure › specified NEC
• Anomaly, anomalous (congenital) (unspecified type) › Eisenmenger's (ventricular septal defect)
• Anomaly, anomalous (congenital) (unspecified type) › heart › septum › specified NEC
• Bulbus cordis (left ventricle) (persistent)
• Defect, defective › Eisenmenger's
• Eisenmenger's › defect
• Fallot's › pentalogy
• Malformation (congenital) › cardiac › septum › specified type NEC
• Pentalogy of Fallot
• Persistence, persistent (congenital) › bulbus cordis in left ventricle
• Premature › closure, foramen ovale

Nearby codes

• Q21.21 Partial atrioventricular septal defect
• Q21.22 Transitional atrioventricular septal defect
• Q21.23 Complete atrioventricular septal defect
• Q21.3 Tetralogy of Fallot
• Q21.4 Aortopulmonary septal defect
• Q21.8 Other congenital malformations of cardiac septa (this code)
• Q21.9 Congenital malformation of cardiac septum, unspecified