2026 ICD-10-CM Diagnosis Code Q03.1Atresia of foramina of Magendie and Luschka

ICD-10-CM Codes›Q00-Q99›Q00-Q07›Q03

ICD-10-CM Q03.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q03.1 is a billable ICD-10-CM diagnosis code for atresia of foramina of Magendie and Luschka. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nervous system congenital anomalies.

Code Identity

ICD-10-CM Code
Q03.1
Billable Status
Yes — Valid for Submission
Code Describes
Atresia of foramina of Magendie and Luschka
Short Description
Atresia of foramina of Magendie and Luschka
Same as the full description in the CMS dataset.
Parent Code
Q03
Congenital hydrocephalus

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ00-Q07Congenital malformations of the nervous system
CategoryQ03Congenital hydrocephalus
This CodeQ03.1Atresia of foramina of Magendie and Luschka

Present on Admission (POA)Billing

Q03.1 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.

  • Congenital anterior polar cataract
  • Congenital atresia of foramen of Luschka
  • Congenital atresia of foramen of Magendie
  • Craniosynostosis with Dandy-Walker malformation and hydrocephalus syndrome
  • Dandy-Walker malformation with postaxial polydactyly syndrome
  • Dandy-Walker syndrome
  • Distal spinal muscular atrophy
  • Facial dysmorphism, macrocephaly, myopia, Dandy-Walker malformation syndrome
  • Hydrocephalus due to Dandy-Walker malformation
  • Spinal muscular atrophy, Dandy-Walker malformation, cataract syndrome

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Dandy-Walker syndrome

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.

    • Atresia, atretic
      • foramen of
        • Luschka
    • Atresia, atretic
      • foramen of
        • Magendie
    • Block, blocked
      • foramen Magendie (acquired)
        • congenital
    • Cyst(colloid) (mucous) (simple) (retention)
      • Dandy-Walker
    • Dandy-Walker syndrome
    • Deformity
      • Dandy-Walker
    • Hydrocephalus(acquired) (external) (internal) (malignant) (recurrent)
      • foramen Magendie block (acquired)
        • congenital
    • Syndrome
      • Dandy-Walker

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

Clinical InformationClinical

  • Congenital Hydrocephalus

    hydrocephalus that is present at birth.

Patient EducationClinical

Brain Malformations

Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it to develop abnormally. Sometimes it's a genetic problem. In other cases, exposure to certain medicines, infections, or radiation during pregnancy interferes with brain development.

Read the full article at MedlinePlus

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

Convert Q03.1 to ICD-9-CMHistory

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

ICD-9-CM
742.3 Congenital hydrocephalus
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 Q03.1Overview

Is Q03.1 (Congenital hydrocephalus) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report atresia of foramina of Magendie and Luschka on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is Q03.1 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 atresia of foramina of Magendie and Luschka on inpatient claims.

What is the ICD-9 equivalent of Q03.1?

Under the General Equivalence Mappings, atresia of foramina of Magendie and Luschka converts to ICD-9-CM 742.3 (congenital hydrocephalus). 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.