Congenital malformations of cardiac chambers and connections (Q20) ICD-10-CM
The Q20 code range covers congenital malformations of cardiac chambers and connections with 10 ICD-10-CM diagnosis codes. 9 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Codes in the Q20 Range 10 codes · 9 billable
- Q20 Congenital malformations of cardiac chambers and connectionsNon-billable
- Q20.0 Common arterial trunk
- 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
- Q20.8 Other congenital malformations of cardiac chambers and connections
- Q20.9 Congenital malformation of cardiac chambers and connections, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the Q20 range.
Double Outlet Right Ventricle
Incomplete transposition of the great vessels in which both the AORTA and the PULMONARY ARTERY arise from the RIGHT VENTRICLE. The only outlet of the LEFT VENTRICLE is a large ventricular septal defect (VENTRICULAR SEPTAL DEFECTS or VSD). The various subtypes are classified by the location of the septal defect, such as subaortic, subpulmonary, or noncommitted.
About the Q20 Code Range
The ICD-10 code Q20 covers congenital malformations of the heart’s chambers and their connections, identifying various structural heart defects present from birth. These codes help specify unique cardiac anomalies such as the common arterial trunk (Q20.0) or double outlet right ventricle (Q20.1), critical for accurate diagnosis and treatment planning.
This group includes detailed codes for conditions like common arterial trunk (Q20.0), also known as truncus arteriosus, where a single arterial trunk arises from the heart instead of separate pulmonary artery and aorta. The double outlet right ventricle (Q20.1) describes a heart in which both great arteries arise from the right ventricle. The section further details less common anomalies such as discordant ventriculoarterial connection (Q20.3) and isomerism of atrial appendages (Q20.6). For example, medical coders can link synonyms like “truncus arteriosus” or “Ebstein’s anomaly” with their correct ICD-10 designation. The Q20.9 code is used when the specific congenital cardiac malformation is not otherwise specified, helping capture cases lacking detailed diagnosis. Utilizing the ICD-10 code for congenital malformations of cardiac chambers and connections enables precise documentation of complex congenital heart diseases.
Questions About This Page
How many billable codes are in the Q20 range?
Of the 10 codes in this range, 9 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the Q20 range classify?
The range classifies congenital malformations of cardiac chambers and connections. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
