I66.0Occlusion and stenosis of middle cerebral artery

I66.0 is the ICD-10-CM diagnosis code for occlusion and stenosis of middle cerebral artery. It belongs to category I66 (occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction), block I60-I69 (cerebrovascular diseases) and chapter 9 (diseases of the circulatory system). It is a header code, so it can't be reported by itself; one of its 4 subcodes must be used instead.

Within I66 (occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction), I66.0 is specifically for occlusion and stenosis of middle cerebral artery. Related codes cover anterior cerebral artery (I66.1), posterior cerebral artery (I66.2), cerebellar arteries (I66.3), other cerebral arteries (I66.8) and unspecified cerebral artery (I66.9).

To report this condition, pick the subcode that matches the documentation: I66.01 (artery), I66.02 (artery), I66.03 (arteries) and I66.09 (artery).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.