Q00.0 Anencephaly

Billable ICD-10-CM code, FY2026. Acts as a Major Complication or Comorbidity (MCC) as a secondary diagnosis. Exempt from present-on-admission (POA) reporting.

Applicable to

• Acephaly
• Acrania
• Amyelencephaly
• Hemianencephaly
• Hemicephaly

Risk adjustment (HCC)

• CMS-HCC V28: HCC 182 — Spinal Cord Disorders/Injuries
• CMS-HCC V22: HCC 72 — Spinal Cord Disorders/Injuries
• RxHCC V08: HCC 155 — Spinal Cord Disorders
• ESRD V24: HCC 72

MS-DRG index

Defines the logic of DRG(s) 091-093 in MDC 01.

Approximate ICD-9-CM (GEMs)

• 740.0 Anencephalus

Code annotations containing back-references to Q00.0

Back-references to Q00.0

• Type 1 Excludes: Q75 Other congenital malformations of skull and face bones ("anencephaly (Q00.0)")

Back-references to Q00

• Type 2 Excludes: P04 Newborn affected by noxious substances transmitted via placenta or breast milk ("congenital malformations (Q00-Q99)")

Diagnosis Index entries for Q00.0

• Absence (of) (organ or part) (complete or partial) › brain
• Absence (of) (organ or part) (complete or partial) › skull bone (congenital) › with › anencephaly
• Acephalia, acephalism, acephalus, acephaly
• Acrania
• Agenesis › brain
• Agenesis › skull (bone) › with › anencephaly
• Amyelencephalus, amyelencephaly
• Anencephalus, anencephaly
• Anomaly, anomalous (congenital) (unspecified type) › bone › skull › with › anencephaly
• Anomaly, anomalous (congenital) (unspecified type) › hemianencephaly
• Anomaly, anomalous (congenital) (unspecified type) › hemicephaly
• Anomaly, anomalous (congenital) (unspecified type) › hemicrania
• Anomaly, anomalous (congenital) (unspecified type) › skull › with › anencephaly
• Aplasia › brain
• Deformity › skull (acquired) › congenital › with › anencephaly
• Distortion (s) (congenital) › skull bone (s) NEC › with › anencephalus
• Hemianencephaly
• Hemicephalus, hemicephaly
• Hemicrania › congenital malformation
• Hypoplasia, hypoplastic › skull (bone) › with › anencephaly
• Imperfect › closure (congenital) › skull › with › anencephaly
• Monster, monstrosity (single) › acephalic

Nearby codes

• Q00 Anencephaly and similar malformations
• Q00.0 Anencephaly (this code)
• Q00.1 Craniorachischisis
• Q00.2 Iniencephaly