Congenital malformations of the nervous system (Q00-Q07) ICD-10-CM
The Q00–Q07 section covers congenital malformations of the nervous system with 53 ICD-10-CM diagnosis codes, of which 45 are billable in fiscal year 2026. The section is organized into the 8 code ranges listed below.
Code Ranges in This Section 8 ranges · 53 codes
The info icon previews the code ranges inside each row and its instructional notations from the official Tabular List.
About the Q00–Q07 Code Range
Q00-Q07 codes in the ICD-10-CM classify congenital malformations of the nervous system, covering a range of structural brain, spinal cord, and nerve defects present at birth.
This chapter includes codes for specific conditions like anencephaly (Q00.0), also known by synonyms such as congenital brain aplasia and acrania, which involve absence of major portions of the brain and skull. The encephalocele group (Q01) refers to brain tissue herniations through skull defects, with types like frontal, nasofrontal (frontoethmoidal), and occipital encephaloceles. Microcephaly (Q02) encompasses various congenital small head conditions often linked to intellectual disability and developmental delay. Congenital hydrocephalus (Q03) codes address abnormal cerebrospinal fluid buildup, including subclasses involving the aqueduct of Sylvius and the foramina of Magendie and Luschka (Dandy-Walker syndrome). Spina bifida (Q05) codes detail defects in spinal closure, differentiated by location and presence of hydrocephalus. Other categories cover malformations of corpus callosum, brain reduction deformities, and Arnold-Chiari syndrome (Q07), a condition involving hindbrain herniation often associated with hydrocephalus or spina bifida. Unspecific or other congenital nervous system anomalies are grouped under unspecified codes to capture broad or rare defects. This ICD chapter aids precise documentation of congenital nervous system anomalies, such as hypoplasia, dysplasia, and cystic malformations.
Questions About This Page
How many codes are in the Q00-Q07 range?
The Q00-Q07 range contains 53 ICD-10-CM diagnosis codes in FY 2026. 45 of them are billable, and the rest are category headers that organize the section.
What conditions does Q00-Q07 cover?
The range covers congenital malformations of the nervous system. The code ranges listed above break it into groups of related conditions, and each one links to its own page with the full code list.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
