Q23.8Other congenital malformations of aortic and mitral valves

Q23.8 is the ICD-10-CM diagnosis code for other congenital malformations of aortic and mitral valves. It belongs to category Q23 (congenital malformations of aortic and mitral valves), block Q20-Q28 (congenital malformations of the circulatory system) and chapter 17 (congenital malformations, deformations, chromosomal abnormalities, and genetic disorders). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within Q23, choose Q23.8 (Other congenital malformations of aortic and mitral valves) only when documentation doesn't support a more specific option: congenital stenosis of aortic valve (Q23.0), congenital insufficiency of aortic valve (Q23.1), congenital mitral stenosis (Q23.2), congenital mitral insufficiency (Q23.3), Hypoplastic left heart syndrome (Q23.4) and congenital malformation of aortic and mitral valves, unspecified (Q23.9).

To report this condition, pick the subcode that matches the documentation: Q23.81 (valve), Q23.82 (leaflet) and Q23.88 (valves).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2025 (expanded into subcodes).

Before ICD-10, this condition was coded in ICD-9-CM as 746.89 (other specified congenital anomalies of heart).