All ICD10 Codes
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)
All CodesBillable Only
Browse by Section12 Sections
Internal Codes
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  • Q00.0|

    Anencephaly

  • Q00.1|

    Craniorachischisis

  • Q00.2|

    Iniencephaly

  • Q01.0|

    Frontal encephalocele

  • Q01.1|

    Nasofrontal encephalocele

  • Q01.2|

    Occipital encephalocele

  • Q01.8|

    Encephalocele of other sites

  • Q01.9|

    Encephalocele, unspecified

  • Q02|

    Microcephaly

  • Q03.0|

    Malformations of aqueduct of Sylvius

  • Q03.1|

    Atresia of foramina of Magendie and Luschka

  • Q03.8|

    Other congenital hydrocephalus

  • Q03.9|

    Congenital hydrocephalus, unspecified

  • Q04.0|

    Congenital malformations of corpus callosum

  • Q04.1|

    Arhinencephaly

  • Q04.2|

    Holoprosencephaly

  • Q04.3|

    Other reduction deformities of brain

  • Q04.4|

    Septo-optic dysplasia of brain

  • Q04.5|

    Megalencephaly

  • Q04.6|

    Congenital cerebral cysts

  • Q04.8|

    Other specified congenital malformations of brain

  • Q04.9|

    Congenital malformation of brain, unspecified

  • Q05.0|

    Cervical spina bifida with hydrocephalus

  • Q05.1|

    Thoracic spina bifida with hydrocephalus

  • Q05.2|

    Lumbar spina bifida with hydrocephalus

  • Q05.3|

    Sacral spina bifida with hydrocephalus

  • Q05.4|

    Unspecified spina bifida with hydrocephalus

  • Q05.5|

    Cervical spina bifida without hydrocephalus

  • Q05.6|

    Thoracic spina bifida without hydrocephalus

  • Q05.7|

    Lumbar spina bifida without hydrocephalus

  • Q05.8|

    Sacral spina bifida without hydrocephalus

  • Q05.9|

    Spina bifida, unspecified

  • Q06.0|

    Amyelia

  • Q06.1|

    Hypoplasia and dysplasia of spinal cord

  • Q06.2|

    Diastematomyelia

  • Q06.3|

    Other congenital cauda equina malformations

  • Q06.4|

    Hydromyelia

  • Q06.8|

    Other specified congenital malformations of spinal cord

  • Q06.9|

    Congenital malformation of spinal cord, unspecified

  • Q07.00|

    Arnold-Chiari syndrome without spina bifida or hydrocephalus

  • Q07.01|

    Arnold-Chiari syndrome with spina bifida

  • Q07.02|

    Arnold-Chiari syndrome with hydrocephalus

  • Q07.03|

    Arnold-Chiari syndrome with spina bifida and hydrocephalus

  • Q07.8|

    Other specified congenital malformations of nervous system

  • Q07.9|

    Congenital malformation of nervous system, unspecified

  • Q10.0|

    Congenital ptosis

  • Q10.1|

    Congenital ectropion

  • Q10.2|

    Congenital entropion

  • Q10.3|

    Other congenital malformations of eyelid

  • Q10.4|

    Absence and agenesis of lacrimal apparatus

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