Is I66 a billable code?
No. I66 is a header code that groups 15 more specific codes. Use one of the billable codes listed on this page instead.
ICD-10-CM FY2027 diagnosis code
I66: Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction
Header code: not billableValid for dates of service October 1, 2026 to September 30, 2027
I66 groups related diagnoses under occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction. It cannot be used on a claim by itself. Choose the billable code below that matches the patient's record.
Billable codes under I66
- I66.01Occlusion and stenosis of right middle cerebral artery
- I66.02Occlusion and stenosis of left middle cerebral artery
- I66.03Occlusion and stenosis of bilateral middle cerebral arteries
- I66.09Occlusion and stenosis of unspecified middle cerebral artery
- I66.11Occlusion and stenosis of right anterior cerebral artery
- I66.12Occlusion and stenosis of left anterior cerebral artery
- I66.13Occlusion and stenosis of bilateral anterior cerebral arteries
- I66.19Occlusion and stenosis of unspecified anterior cerebral artery
- I66.21Occlusion and stenosis of right posterior cerebral artery
- I66.22Occlusion and stenosis of left posterior cerebral artery
- I66.23Occlusion and stenosis of bilateral posterior cerebral arteries
- I66.29Occlusion and stenosis of unspecified posterior cerebral artery
- I66.3Occlusion and stenosis of cerebellar arteries
- I66.8Occlusion and stenosis of other cerebral arteries
- I66.9Occlusion and stenosis of unspecified cerebral artery
I66 questions
What does I66 mean?
I66 is the ICD-10-CM code for Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction. It is in chapter 9, Diseases of the circulatory system (I00-I99).
Code titles come from the official ICD-10-CM files published by the CDC National Center for Health Statistics. Always check payer rules and the clinical record before billing.