2026 ICD-10-CM Diagnosis Code I65.21Occlusion and stenosis of right carotid artery

ICD-10-CM Codes›I00–I99›I60-I69›I65

ICD-10-CM I65.21
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I65.21 is a billable ICD-10-CM diagnosis code for occlusion and stenosis of right carotid 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 Occlusion or stenosis of precerebral or cerebral arteries without infarction.

Code Identity

ICD-10-CM Code
I65.21
Billable Status
Yes — Valid for Submission
Code Describes
Occlusion and stenosis of right carotid artery
Short Description
Occlusion and stenosis of right carotid artery
Same as the full description in the CMS dataset.
Parent Code
I65.2
Occlusion and stenosis of carotid artery

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI60-I69Cerebrovascular diseases
CategoryI65Occlusion and stenosis of precerebral arteries, not resulting in cerebral infarction
This CodeI65.21Occlusion and stenosis of right carotid artery

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carotid artery embolism
  • Carotid artery obstruction
  • Carotid artery occlusion
  • Carotid artery thrombosis
  • Embolism of right carotid artery
  • Internal carotid artery stenosis
  • Occlusive embolus of right carotid artery
  • Right carotid artery occlusion
  • Right carotid artery stenosis
  • Stenosis of cavernous portion of right internal carotid artery
  • Thrombosis of internal carotid artery
  • Thrombosis of right carotid artery
  • Thrombosis of right internal carotid artery

Clinical ClassificationClinical

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

CCSR CIR023
Occlusion or stenosis of precerebral or cerebral arteries without infarction
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Carotid Artery Thrombosis

    blood clot formation in any part of the carotid arteries. this may produce carotid stenosis or occlusion of the vessel, leading to transient ischemic attack; cerebral infarction; or amaurosis fugax.

Patient EducationClinical

Carotid Artery Disease

Your carotid arteries are two large blood vessels in your neck. They supply your brain and head with blood. If you have carotid artery disease, the arteries become narrow or blocked, usually because of atherosclerosis.

Read the full article at MedlinePlus

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

Convert I65.21 to ICD-9-CMHistory

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

ICD-9-CM
433.10 Ocl crtd art wo infrct
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 I65.21Overview

Is I65.21 (Occlusion and stenosis of carotid artery) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report occlusion and stenosis of right carotid artery on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of I65.21?

Under the General Equivalence Mappings, occlusion and stenosis of right carotid artery converts to ICD-9-CM 433.10 (ocl crtd art wo infrct). 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.