Chapter 17

Q00–Q99: Congenital Malformations, Deformations and Chromosomal Abnormalities

Congenital Malformations, Deformations and Chromosomal Abnormalities diagnostic classification updated for 2026.

Chapter Instructions

Excludes2(Not included here. Code separately if applicable.)
  • inborn errors of metabolism (E70-E88)
Internal Codes
  • Q23.9|

    Congenital malformation of aortic and mitral valves, unspecified

  • Q24.0|

    Dextrocardia

  • Q24.1|

    Levocardia

  • Q24.2|

    Cor triatriatum

  • Q24.3|

    Pulmonary infundibular stenosis

  • Q24.4|

    Congenital subaortic stenosis

  • Q24.5|

    Malformation of coronary vessels

  • Q24.6|

    Congenital heart block

  • Q24.8|

    Other specified congenital malformations of heart

  • Q24.9|

    Congenital malformation of heart, unspecified

  • Q25.0|

    Patent ductus arteriosus

  • Q25.1|

    Coarctation of aorta

  • Q25.21|

    Interruption of aortic arch

  • Q25.29|

    Other atresia of aorta

  • Q25.3|

    Supravalvular aortic stenosis

  • Q25.40|

    Congenital malformation of aorta unspecified

  • Q25.41|

    Absence and aplasia of aorta

  • Q25.42|

    Hypoplasia of aorta

  • Q25.43|

    Congenital aneurysm of aorta

  • Q25.44|

    Congenital dilation of aorta

  • Q25.45|

    Double aortic arch

  • Q25.46|

    Tortuous aortic arch

  • Q25.47|

    Right aortic arch

  • Q25.48|

    Anomalous origin of subclavian artery

  • Q25.49|

    Other congenital malformations of aorta

  • Q25.5|

    Atresia of pulmonary artery

  • Q25.6|

    Stenosis of pulmonary artery

  • Q25.71|

    Coarctation of pulmonary artery

  • Q25.72|

    Congenital pulmonary arteriovenous malformation

  • Q25.79|

    Other congenital malformations of pulmonary artery

  • Q25.8|

    Other congenital malformations of other great arteries

  • Q25.9|

    Congenital malformation of great arteries, unspecified

  • Q26.0|

    Congenital stenosis of vena cava

  • Q26.1|

    Persistent left superior vena cava

  • Q26.2|

    Total anomalous pulmonary venous connection

  • Q26.3|

    Partial anomalous pulmonary venous connection

  • Q26.4|

    Anomalous pulmonary venous connection, unspecified

  • Q26.5|

    Anomalous portal venous connection

  • Q26.6|

    Portal vein-hepatic artery fistula

  • Q26.8|

    Other congenital malformations of great veins

  • Q26.9|

    Congenital malformation of great vein, unspecified

  • Q27.0|

    Congenital absence and hypoplasia of umbilical artery

  • Q27.1|

    Congenital renal artery stenosis

  • Q27.2|

    Other congenital malformations of renal artery

  • Q27.30|

    Arteriovenous malformation, site unspecified

  • Q27.31|

    Arteriovenous malformation of vessel of upper limb

  • Q27.32|

    Arteriovenous malformation of vessel of lower limb

  • Q27.33|

    Arteriovenous malformation of digestive system vessel

  • Q27.34|

    Arteriovenous malformation of renal vessel

  • Q27.39|

    Arteriovenous malformation, other site

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