2026 ICD-10-CM Diagnosis Code Q07.02Arnold-Chiari syndrome with hydrocephalus

ICD-10-CM Codes›Q00-Q99›Q00-Q07›Q07

ICD-10-CM Q07.02
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q07.02 is a billable ICD-10-CM diagnosis code for Arnold-Chiari syndrome with hydrocephalus. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is exempt from POA reporting. Coders also document this condition as chiari malformation. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nervous system congenital anomalies.

Code Identity

ICD-10-CM Code
Q07.02
Billable Status
Yes — Valid for Submission
Code Describes
Arnold-Chiari syndrome with hydrocephalus
Short Description
Arnold-Chiari syndrome with hydrocephalus
Same as the full description in the CMS dataset.
Parent Code
Q07.0
Arnold-Chiari syndrome

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ00-Q07Congenital malformations of the nervous system
CategoryQ07Other congenital malformations of nervous system
This CodeQ07.02Arnold-Chiari syndrome with hydrocephalus

Present on Admission (POA)Billing

Q07.02 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Chiari malformation
  • Chiari malformation type II
  • Hydrocephalus due to Arnold Chiari malformation
  • Hydrocephalus due to Arnold Chiari malformation type 2
  • Obstructive hydrocephalus

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Arnold-Chiari disease, obstruction or syndrome(type II)
      • with
        • hydrocephalus

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MAL004
Nervous system congenital anomalies
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Chiari Malformation

Chiari malformations (CMs) are structural defects in the cerebellum. The cerebellum is the part of the brain that controls balance. With CM, brain tissue extends into the spinal canal. It can happen when part of the skull is too small, which pushes the brain tissue down. There are several types of CM.

Read the full article at MedlinePlus

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

Convert Q07.02 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
741.00 Spin bif w hydroceph NOS
Approximate The match is approximate rather than exact.

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 Q07.02Overview

Is Q07.02 (Arnold-Chiari syndrome) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report Arnold-Chiari syndrome with hydrocephalus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is Q07.02 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for Arnold-Chiari syndrome with hydrocephalus on inpatient claims.

What is the ICD-9 equivalent of Q07.02?

Under the General Equivalence Mappings, Arnold-Chiari syndrome with hydrocephalus converts to ICD-9-CM 741.00 (spin bif w hydroceph NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.