2027 ICD-10-CM Diagnosis Code I67.5Moyamoya disease
ICD-10-CM Codes›I00–I99›I60-I69›I67
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Chronic Condition
I67.5 is a billable ICD-10-CM diagnosis code for moyamoya disease. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 91 through 93. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 62 closely related codes. 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
Code Classification
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
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to I67.5: its own notes plus those printed at I67, block I60-I69, and Chapter 9. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- traumatic intracranial hemorrhage (S06.-)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- sequelae of the listed conditions (I69.8)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
- systemic connective tissue disorders (M30-M36)
- transient cerebral ischemic attacks and related syndromes (G45.-)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disease, diseased See Also: Syndrome;
moyamoya I67.5
Nishimoto (-Takeuchi) I67.5
Moyamoya disease I67.5
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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.
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.
Code HistoryHistory
Questions About I67.5Overview
What is the ICD-10 code for moyamoya disease?
The ICD-10-CM code for moyamoya disease is I67.5 (sometimes written as I675). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
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, 2026 through September 30, 2027.
What MS-DRG does I67.5 group to?
When moyamoya disease is the principal diagnosis on an inpatient stay, it groups to MS-DRG 91, 92, 93, with relative weights from 0.7783 to 1.7050 depending on complications. Higher weights mean higher Medicare reimbursement.
Is I67.5 a CC or MCC?
CMS lists I67.5 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 62 closely related codes in its exclusion list.
Can I67.5 be reported with a code from I63.2?
Not as a rule. The Excludes1 note at I67, which applies to I67.5, lists "Occlusion and stenosis of precerebral artery causing cerebral infarction (I63.2-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
