Q00.0 Anencephaly

✓ Billable ICD-10-CM 2026
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The ICD-10-CM code for Anencephaly is Q00.0 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Section
Q00-Q07: Congenital malformations of the nervous system (Q00-Q07)
Category Q00
4 codes (3 billable)
FY2026 Status
Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to Q00.0:

  • Amyelencephalus, amyelencephaly
  • Acrania
  • Acephalia, acephalism, acephalus, acephaly
  • Hemianencephaly
  • Hemicephalus, hemicephaly
  • Anencephalus, anencephaly
  • Agenesis › brain
  • Absence (of) (organ or part) (complete or partial) › brain

Inclusion Terms

  • Acephaly
  • Acrania
  • Amyelencephaly
  • Hemianencephaly
  • Hemicephaly

U.S. Hospital Utilization

  • An estimated 330 U.S. inpatient stays in 2023 included Q00.0 among the documented diagnoses.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Assign Q00-QA1 when malformation/deformation/chromosomal abnormality documented

17. Chapter 17: Congenital malformations, deformations, and chromosomal abnormalities (Q00-QA1) Assign an appropriate code(s) from categories Q00-QA1, Congenital malformations, deformations, and chromosomal abnormalities when a malformation/deformation or chromosomal abnormality is documented. A malformation/deformation/or chromosomal abnormality may be the principal/first-listed diagnosis on a record or a secondary diagnosis.

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.17
Chapter 17 codes usable throughout life; assign Q00-QA1 when diagnosed

Codes from Chapter 17 may be used throughout the life of the patient. If a congenital malformation or deformity has been corrected, a personal history code should be used to identify the history of the malformation or deformity. Although present at birth, a malformation/deformation/or chromosomal abnormality may not be identified until later in life. Whenever the condition is diagnosed by the provider, it is appropriate to assign a code from codes Q00-QA1.

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.17

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

Related Codes

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Reviewed by Prajwal Shrestha, CPC, CRC
Certified Professional Coder (CPC) and Certified Risk Adjustment Coder (CRC) · AAPC Member ID 01997614 · About · Editorial policy · Content last reviewed: 2025-10-01

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