2026 ICD-10-CM Diagnosis Code I63.539Cerebral infarction due to unspecified occlusion or stenosis of unspecified posterior cerebral artery

ICD-10-CM Codes›I00–I99›I60-I69›I63

ICD-10-CM I63.539
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I63.539 is a billable ICD-10-CM diagnosis code for cerebral infarction due to unspecified occlusion or stenosis of unspecified posterior cerebral artery. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Cerebral infarction.

Code Identity

ICD-10-CM Code
I63.539
Billable Status
Yes — Valid for Submission
Code Describes
Cerebral infarction due to unspecified occlusion or stenosis of unspecified posterior cerebral artery
Short Description
Cereb infrc d/t unsp occls or stenos of unsp post cereb art
Parent Code
I63.53
Cerebral infarction due to unspecified occlusion or stenosis of posterior cerebral artery

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI60-I69Cerebrovascular diseases
CategoryI63Cerebral infarction
This CodeI63.539Cerebral infarction due to unspecified occlusion or stenosis of unspecified posterior cerebral artery

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Brain stem infarction
  • Cerebellar stroke
  • Cerebral infarction due to cerebral artery occlusion
  • Cerebral infarction due to posterior cerebral artery occlusion
  • Intracranial artery occlusion with infarction
  • Necrosis of artery
  • Occlusion and stenosis of posterior cerebral artery
  • Occlusion and stenosis of posterior cerebral artery with infarction
  • Posterior cerebral circulation infarction
  • Posterior inferior cerebellar artery occlusion with infarction
  • Top of basilar syndrome

Clinical ClassificationClinical

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

CCSR CIR020
Cerebral infarction
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Ischemic Stroke

A stroke happens when there is a loss of blood flow to part of the brain. Your brain cells cannot get the oxygen and nutrients they need from blood, and they start to die within a few minutes. This can cause lasting brain damage, long-term disability, or even death.

The full article covers:

  • What is an ischemic stroke?
  • What causes an ischemic stroke?
  • What are the symptoms of ischemic stroke?
  • How is an ischemic stroke diagnosed?
  • How is an ischemic stroke treated?
  • Can an ischemic stroke be prevented?

Read the full article at MedlinePlus

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

Convert I63.539 to ICD-9-CMHistory

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

ICD-9-CM
434.91 Crbl art ocl NOS w infrc
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 I63.539Overview

Is I63.539 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report cerebral infarction due to unspecified occlusion or stenosis of unspecified posterior cerebral artery on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of I63.539?

Under the General Equivalence Mappings, cerebral infarction due to unspecified occlusion or stenosis of unspecified posterior cerebral artery converts to ICD-9-CM 434.91 (crbl art ocl NOS w infrc). 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.