2026 ICD-10-CM Diagnosis Code I67.5Moyamoya disease

ICD-10-CM Codes›I00–I99›I60-I69›I67

ICD-10-CM I67.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I67.5 is a billable ICD-10-CM diagnosis code for moyamoya disease. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as achalasia of esophagus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other and ill-defined cerebrovascular disease.

Code Identity

ICD-10-CM Code
I67.5
Billable Status
Yes — Valid for Submission
Code Describes
Moyamoya disease
Short Description
Moyamoya disease
Same as the full description in the CMS dataset.
Parent Code
I67
Other cerebrovascular diseases

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI60-I69Cerebrovascular diseases
CategoryI67Other cerebrovascular diseases
This CodeI67.5Moyamoya disease

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Achalasia of esophagus
  • Congenital stenosis of carotid artery
  • Internal carotid artery stenosis
  • Moyamoya angiopathy, short stature, facial dysmorphism, hypergonadotropic hypogonadism syndrome
  • Moyamoya disease
  • Moyamoya disease with early onset achalasia
  • Secondary moyamoya disease
  • Stenosis of intracranial carotid artery

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.

    • Disease, diseased
      • moyamoya
    • Disease, diseased
      • Nishimoto (-Takeuchi)
    • Encephaloduroarteriomyosynangiosis(EDAMS)
    • Moyamoya disease
    • Nishimoto(-Takeuchi) disease

Clinical ClassificationClinical

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

CCSR CIR024
Other and ill-defined cerebrovascular disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Moyamoya Disease

    a noninflammatory, progressive occlusion of the intracranial carotid arteries and the formation of netlike collateral arteries arising from the circle of willis. cerebral angiogram shows the puff-of-smoke (moyamoya) collaterals at the base of the brain. it is characterized by endothelial hyperplasia and fibrosis with thickening of arterial walls. this disease primarily affects children but can also occur in adults.

  • Moyamoya Disease

    a rare inherited vascular disorder characterized by constriction of arteries at the base of the brain, resulting in the formation of collateral circulation in order to compensate for the constriction. the name "moyamoya" in japanese means "puff of smoke" and derives from the characteristic radiographic appearance of the collateral vessels.

  • Moyamoya Disease 2|MYMY2

    an autosomally inherited subtype of moyamoya disease often presenting in childhood caused by mutation(s) in the rnf213 gene, encoding e3 ubiquitin-protein ligase rnf213.

  • RNF213 wt Allele|ALK Lymphoma Oligomerization Partner on Chromosome 17 Gene|ALO17|C17orf27|Chromosome 17 Open Reading Frame 27 Gene|DKFZp762N1115|FLJ13051|KIAA1554|KIAA1618|MGC46622|MGC9929|MYMY2|MYSTR|Moyamoya Disease 2 Gene|NET57|Ring Finger Protein 213 wt Allele|hCG_1812857

    human rnf213 wild-type allele is located in the vicinity of 17q25.3 and is approximately 135 kb in length. this allele, which encodes e3 ubiquitin-protein ligase rnf213 protein, may play a role in the regulation of protein ubiquitination. a chromosomal translocation t(2;17)(p23;q25) of this gene with the alk gene is associated with anaplastic large cell lymphoma.

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 I67.5 to ICD-9-CMHistory

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

ICD-9-CM
437.5 Moyamoya disease
Exact Match The mapping is direct, with no qualifiers.

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 I67.5Overview

Is I67.5 (Other cerebrovascular diseases) a billable code?

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

What is the ICD-9 equivalent of I67.5?

Under the General Equivalence Mappings, moyamoya disease converts to ICD-9-CM 437.5 (moyamoya disease). The mapping is a direct match.

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.