Q20.6Isomerism of atrial appendages

Q20.6 is the ICD-10-CM diagnosis code for Isomerism of atrial appendages. It belongs to category Q20 (congenital malformations of cardiac chambers and connections), block Q20-Q28 (congenital malformations of the circulatory system) and chapter 17 (congenital malformations, deformations, chromosomal abnormalities, and genetic disorders). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within Q20 (congenital malformations of cardiac chambers and connections), Q20.6 is specifically for Isomerism of atrial appendages. Related codes cover common arterial trunk (Q20.0), Double outlet right ventricle (Q20.1), Double outlet left ventricle (Q20.2), Discordant ventriculoarterial connection (Q20.3), Double inlet ventricle (Q20.4), Discordant atrioventricular connection (Q20.5), other congenital malformations of cardiac chambers and connections (Q20.8) and congenital malformation of cardiac chambers and connections, unspecified (Q20.9).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 306 (Cardiac Congenital and Valvular Disorders with MCC, relative weight 1.546) and DRG 307 (Cardiac Congenital and Valvular Disorders without MCC, relative weight 0.9148), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 745.8 (other bulbus cordis anomalies and anomalies of cardiac septal closure).