Congenital malformations of aortic and mitral valves (Q23) ICD-10-CM
The Q23 code range covers congenital malformations of aortic and mitral valves with 11 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.
Codes in the Q23 Range 11 codes · 9 billable
- Q23 Congenital malformations of aortic and mitral valvesNon-billable
- Q23.0 Congenital stenosis of aortic valve
- Q23.1 Congenital insufficiency of aortic valve
- Q23.2 Congenital mitral stenosis
- Q23.3 Congenital mitral insufficiency
- Q23.4 Hypoplastic left heart syndrome
- Q23.8 Other congenital malformations of aortic and mitral valvesNon-billable
- Q23.81 Bicuspid aortic valve
- Q23.82 Congenital mitral valve cleft leaflet
- Q23.88 Other congenital malformations of aortic and mitral valves
- Q23.9 Congenital malformation of aortic and mitral valves, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the Q23 range.
Hypoplastic Left Heart Syndrome
A condition caused by underdevelopment of the whole left half of the heart. It is characterized by hypoplasia of the left cardiac chambers (HEART ATRIUM; HEART VENTRICLE), the AORTA, the AORTIC VALVE, and the MITRAL VALVE. Severe symptoms appear in early infancy when DUCTUS ARTERIOSUS closes.
Quadricuspid Aortic Valve
Congenital malformation where the AORTIC VALVE has four instead of three cusps. It is often associated with AORTIC REGURGITATION and AORTIC VALVE STENOSIS.
About the Q23 Code Range
ICD-10 code Q23 covers a group of congenital malformations affecting the aortic and mitral heart valves, essential for proper blood flow through the heart. These codes specify various structural abnormalities present from birth, such as stenosis (narrowing) or insufficiency (leakage) of these valves.
The section includes distinct codes like Q23.0 for congenital stenosis of the aortic valve, often referenced by terms like "bicuspid valve calcification" or "aortic valve atresia." Q23.1 captures congenital aortic valve insufficiency, which can be known as "bicuspid aortic valve" or "congenital prolapse of aortic valve." Mitral valve issues are detailed under Q23.2 for mitral stenosis and Q23.3 for mitral insufficiency, linked with terms such as "parachute mitral valve" or "mitral regurgitation of newborn." More complex syndromes, including Q23.4 for hypoplastic left heart syndrome, highlight critical congenital defects. Other specified forms like bicuspid aortic valve (Q23.81) and congenital mitral valve cleft (Q23.82) are also cataloged. The unspecified malformations fall under Q23.9. This coding section helps clinicians, coders, and researchers accurately identify congenital valve conditions via ICD-10 codes.
Questions About This Page
How many billable codes are in the Q23 range?
Of the 11 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 Q23 range classify?
The range classifies congenital malformations of aortic and mitral valves. 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.
