Q20.6 Isomerism of atrial appendages

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

Applicable to

• Isomerism of atrial appendages with asplenia or polysplenia

Applies from Q20 Congenital malformations of cardiac chambers and connections

Excludes1 (never code together)

• dextrocardia with situs inversus (Q89.3)
• mirror-image atrial arrangement with situs inversus (Q89.3)

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 Q20.6

Back-references to Q20.6

• Type 1 Excludes: Q24.0 Dextrocardia ("isomerism of atrial appendages (with asplenia or polysplenia) (Q20.6)")
• Type 1 Excludes: Q89.0 Congenital absence and malformations of spleen ("isomerism of atrial appendages (with asplenia or polysplenia) (Q20.6)")

Back-references to Q20

• 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: Z71.87 Encounter for pediatric-to-adult transition counseling ("congenital malformations of the circulatory system (Q20-Q28)")

Diagnosis Index entries for Q20.6

• Isomerism atrial appendages (with asplenia or polysplenia)

Nearby codes

• Q20.1 Double outlet right ventricle
• Q20.2 Double outlet left ventricle
• Q20.3 Discordant ventriculoarterial connection
• Q20.4 Double inlet ventricle
• Q20.5 Discordant atrioventricular connection
• Q20.6 Isomerism of atrial appendages (this code)
• Q20.8 Other congenital malformations of cardiac chambers and connections
• Q20.9 Congenital malformation of cardiac chambers and connections, unspecified