ICD-10-CM I66: Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction

ICD-10-CM Diagnosis Code (2025)

Official Description for I66

Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction

Coding Notes & Guidelines for I66

Includes Notes
  • embolism of cerebral artery
  • narrowing of cerebral artery
  • obstruction (complete) (partial) of cerebral artery
  • thrombosis of cerebral artery
Excludes1: Not Coded Here

Occlusion and stenosis of cerebral artery causing cerebral infarction (I63.3-I63.5)

Inclusion Terms

Occlusion and stenosis of perforating arteries

Child Codes (More Specific Codes for I66):

I66.0 - Occlusion and stenosis of middle cerebral artery I66.01 - Occlusion and stenosis of right middle cerebral artery I66.02 - Occlusion and stenosis of left middle cerebral artery I66.03 - Occlusion and stenosis of bilateral middle cerebral arteries I66.09 - Occlusion and stenosis of unspecified middle cerebral artery I66.1 - Occlusion and stenosis of anterior cerebral artery I66.11 - Occlusion and stenosis of right anterior cerebral artery I66.12 - Occlusion and stenosis of left anterior cerebral artery I66.13 - Occlusion and stenosis of bilateral anterior cerebral arteries I66.19 - Occlusion and stenosis of unspecified anterior cerebral artery I66.2 - Occlusion and stenosis of posterior cerebral artery I66.21 - Occlusion and stenosis of right posterior cerebral artery I66.22 - Occlusion and stenosis of left posterior cerebral artery I66.23 - Occlusion and stenosis of bilateral posterior cerebral arteries I66.29 - Occlusion and stenosis of unspecified posterior cerebral artery I66.3 - Occlusion and stenosis of cerebellar arteries I66.8 - Occlusion and stenosis of other cerebral arteries I66.9 - Occlusion and stenosis of unspecified cerebral artery

About ICD-10-CM Code I66 (Occlusion and stenosis of cerebral arteries)

ICD-10-CM code I66 is a billable or specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. The 2025 edition of ICD-10-CM I66 became effective on October 1, 2024.

This page provides detailed information about I66 - Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction. It includes common terminology, coding guidelines such as "Includes," "Excludes1," and "Excludes2" notes, and information on required 7th characters. Utilizing this information correctly is essential for accurate medical coding and claims submission for conditions like Occlusion and stenosis of cerebral arteries related to not resulting in cerebral infarction.