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
  • Q43.9|

    Congenital malformation of intestine, unspecified

  • Q44.0|

    Agenesis, aplasia and hypoplasia of gallbladder

  • Q44.1|

    Other congenital malformations of gallbladder

  • Q44.2|

    Atresia of bile ducts

  • Q44.3|

    Congenital stenosis and stricture of bile ducts

  • Q44.4|

    Choledochal cyst

  • Q44.5|

    Other congenital malformations of bile ducts

  • Q44.6|

    Cystic disease of liver

  • Q44.70|

    Other congenital malformation of liver, unspecified

  • Q44.71|

    Alagille syndrome

  • Q44.79|

    Other congenital malformations of liver

  • Q45.0|

    Agenesis, aplasia and hypoplasia of pancreas

  • Q45.1|

    Annular pancreas

  • Q45.2|

    Congenital pancreatic cyst

  • Q45.3|

    Other congenital malformations of pancreas and pancreatic duct

  • Q45.8|

    Other specified congenital malformations of digestive system

  • Q45.9|

    Congenital malformation of digestive system, unspecified

  • Q50.01|

    Congenital absence of ovary, unilateral

  • Q50.02|

    Congenital absence of ovary, bilateral

  • Q50.1|

    Developmental ovarian cyst

  • Q50.2|

    Congenital torsion of ovary

  • Q50.31|

    Accessory ovary

  • Q50.32|

    Ovarian streak

  • Q50.39|

    Other congenital malformation of ovary

  • Q50.4|

    Embryonic cyst of fallopian tube

  • Q50.5|

    Embryonic cyst of broad ligament

  • Q50.6|

    Other congenital malformations of fallopian tube and broad ligament

  • Q51.0|

    Agenesis and aplasia of uterus

  • Q51.10|

    Doubling of uterus with doubling of cervix and vagina without obstruction

  • Q51.11|

    Doubling of uterus with doubling of cervix and vagina with obstruction

  • Q51.21|

    Complete doubling of uterus

  • Q51.22|

    Partial doubling of uterus

  • Q51.28|

    Other and unspecified doubling of uterus

  • Q51.3|

    Bicornate uterus

  • Q51.4|

    Unicornate uterus

  • Q51.5|

    Agenesis and aplasia of cervix

  • Q51.6|

    Embryonic cyst of cervix

  • Q51.7|

    Congenital fistulae between uterus and digestive and urinary tracts

  • Q51.810|

    Arcuate uterus

  • Q51.811|

    Hypoplasia of uterus

  • Q51.818|

    Other congenital malformations of uterus

  • Q51.820|

    Cervical duplication

  • Q51.821|

    Hypoplasia of cervix

  • Q51.828|

    Other congenital malformations of cervix

  • Q51.9|

    Congenital malformation of uterus and cervix, unspecified

  • Q52.0|

    Congenital absence of vagina

  • Q52.10|

    Doubling of vagina, unspecified

  • Q52.11|

    Transverse vaginal septum

  • Q52.120|

    Longitudinal vaginal septum, nonobstructing

  • Q52.121|

    Longitudinal vaginal septum, obstructing, right side

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