ICD-10-CM > I00-I99 > I60-I69 > I66 > I66.0 I66.0 Occlusion and stenosis of middle cerebral artery Non-Billable/Non-Specific Codes I66.01Occlusion and stenosis of right middle cerebral arteryI66.02Occlusion and stenosis of left middle cerebral arteryI66.03Occlusion and stenosis of bilateral middle cerebral arteriesI66.09Occlusion and stenosis of unspecified middle cerebral artery