ICD-10-CM > Q00-QA0 > Q20-Q28 > Q23 Q23 Congenital malformations of aortic and mitral valves Non-Billable/Non-Specific Codes Q23.0Congenital stenosis of aortic valveQ23.1Congenital insufficiency of aortic valveQ23.2Congenital mitral stenosisQ23.3Congenital mitral insufficiencyQ23.4Hypoplastic left heart syndromeQ23.8Other congenital malformations of aortic and mitral valvesQ23.81Bicuspid aortic valveQ23.82Congenital mitral valve cleft leafletQ23.88Other congenital malformations of aortic and mitral valvesQ23.9Congenital malformation of aortic and mitral valves, unspecified