Q00

Non-Billable
ChapterQ00–Q99
Rankcategory
Official Description

Anencephaly and similar malformations

Metadata & Insights
  • •2026 ICD-10-CM Edition - Effective October 1, 2025.
  • •Non-billable category (requires more specific sub-code).
  • •Chapter 17: Congenital Malformations, Deformations and Chromosomal Abnormalities (Q00-Q99).

CH17 Parent Instructions

Excludes2(Not included here)
  • inborn errors of metabolism (E70-E88)

Clinical Hierarchy

CH17Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0)
Q00-Q07Congenital malformations of the nervous system (Q00-Q07)
Q00Anencephaly and similar malformations
Q00.0Anencephaly
Q00.1Craniorachischisis
Q00.2Iniencephaly

Applicable Ancestor Context

The following parent sections contain instructions or notes that apply to Q00:

chapterCH17
Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0)
View context instructions

Alphabetic Index Mentions

These are Diagnosis Index lookup paths that route to Q00. Use them as entry terms for search, then confirm final coding instructions in the Tabular List and notes above.

24 raw paths
Absence (of) (organ or part) (complete or partial)2 unique routes
brain→Q00
skull bone (congenital)
with
anencephaly→Q00
Acephalia, acephalism, acephalus, acephaly1 unique routes
Direct index entry→Q00
Acrania1 unique routes
Direct index entry→Q00
Agenesis2 unique routes
brain→Q00
skull (bone)
with
anencephaly→Q00
Amyelencephalus, amyelencephaly1 unique routes
Direct index entry→Q00
Anencephalus, anencephaly1 unique routes
Direct index entry→Q00
Anomaly, anomalous (congenital) (unspecified type)5 unique routes
bone
skull
with
anencephaly→Q00
hemianencephaly→Q00
hemicephaly→Q00
hemicrania→Q00
skull
with
anencephaly→Q00
Aplasia1 unique routes
brain→Q00
Craniorachischisis (totalis)1 unique routes
Direct index entry→Q00
Deformity1 unique routes
skull (acquired)
congenital
with
anencephaly→Q00
Distortion (s) (congenital)1 unique routes
skull bone (s) NEC
with
anencephalus→Q00
Hemianencephaly1 unique routes
Direct index entry→Q00
Hemicephalus, hemicephaly1 unique routes
Direct index entry→Q00
Hemicrania1 unique routes
congenital malformation→Q00
Hypoplasia, hypoplastic1 unique routes
skull (bone)
with
anencephaly→Q00
Imperfect1 unique routes
closure (congenital)
skull
with
anencephaly→Q00
Iniencephalus, iniencephaly1 unique routes
Direct index entry→Q00
Monster, monstrosity (single)1 unique routes
acephalic→Q00

MS-DRG Classification

2026

No direct MS-DRG triggers identified.

Cross Reference

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