2026 ICD-10-CM Diagnosis Code Q00Anencephaly and similar malformations

ICD-10-CM Codes›Q00-Q99›Q00-Q07›Q00

ICD-10-CM Q00
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q00 is a non-billable ICD-10-CM category code for anencephaly and similar malformations, so it cannot be submitted on claims. Use a more specific code from this category instead, such as Q00.0, Q00.1, and Q00.2.

Code Identity

ICD-10-CM Code
Q00
Billable Status
No — Non-Billable Category
Code Describes
Anencephaly and similar malformations
Chapter
Q00-Q07
Congenital malformations of the nervous system

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ00-Q07Congenital malformations of the nervous system
CategoryQ00Anencephaly and similar malformations
This CodeQ00Anencephaly and similar malformations

Specific Coding for Anencephaly and similar malformationsOverview

Non-specific codes like Q00 require more characters. Use one of these billable codes instead:

  • Use Q00.0 for Anencephaly

  • Use Q00.1 for Craniorachischisis

  • Use Q00.2 for Iniencephaly

Patient EducationClinical

Neural Tube Defects

Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the first month of pregnancy, often before a woman even knows that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In spina bifida, the fetal spinal column doesn't close completely.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Q00Overview

Is Q00 (Anencephaly and similar malformations) a billable code?

No. This is a category header that groups the codes for anencephaly and similar malformations, and headers cannot be submitted on claims. Claims for anencephaly and similar malformations need a more specific code from this category, such as Q00.0, Q00.1, and Q00.2.