Anencephaly and similar malformations (Q00) ICD-10-CM
The Q00 code range covers anencephaly and similar malformations with 4 ICD-10-CM diagnosis codes. 3 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Codes in the Q00 Range 4 codes · 3 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the Q00 range.
Anencephaly
A malformation of the nervous system caused by failure of the anterior neuropore to close. Infants are born with intact spinal cords, cerebellums, and brainstems, but lack formation of neural structures above this level. The skull is only partially formed but the eyes are usually normal. This condition may be associated with folate deficiency. Affected infants are only capable of primitive (brain stem) reflexes and usually do not survive for more than two weeks. (From Menkes, Textbook of Child Neurology, 5th ed, p247)
Craniorachischisis
A rare and severe form of neural tube defect in which there are open cranial and open spinal defects at birth.
Iniencephaly
A rare neural tube defect characterized by extreme retroflexion of the head and severe defects of the spine. It is usually associated with other congenital anomalies.
About the Q00 Code Range
These conditions are differences in the nervous system present at birth. Q00 groups anencephaly and similar malformations.
Its subdivisions distinguish three named conditions: Q00.0 for anencephaly, Q00.1 for craniorachischisis, and Q00.2 for iniencephaly.
Questions About This Page
How many billable codes are in the Q00 range?
Of the 4 codes in this range, 3 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the Q00 range classify?
The range classifies anencephaly and similar malformations. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
