ICD-10-CM · Chapter 9 · I00-I99
I66 Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction
Includes
- embolism of cerebral artery
- narrowing of cerebral artery
- obstruction (complete) (partial) of cerebral artery
- thrombosis of cerebral artery
Excludes 1 (cannot be coded together)
- Occlusion and stenosis of cerebral artery causing cerebral infarction (I63.3-I63.5)
Subcodes
Each subcode links to a detail page with full clinical annotations.
| Code | Description | Billable |
|---|---|---|
| I66..0 | Occlusion and stenosis of middle cerebral artery | No |
| I66..01 | Occlusion and stenosis of right middle cerebral artery | Yes |
| I66..02 | Occlusion and stenosis of left middle cerebral artery | Yes |
| I66..03 | Occlusion and stenosis of bilateral middle cerebral arteries | Yes |
| I66..09 | Occlusion and stenosis of unspecified middle cerebral artery | Yes |
| I66..1 | Occlusion and stenosis of anterior cerebral artery | No |
| I66..11 | Occlusion and stenosis of right anterior cerebral artery | Yes |
| I66..12 | Occlusion and stenosis of left anterior cerebral artery | Yes |
| I66..13 | Occlusion and stenosis of bilateral anterior cerebral arteries | Yes |
| I66..19 | Occlusion and stenosis of unspecified anterior cerebral artery | Yes |
| I66..2 | Occlusion and stenosis of posterior cerebral artery | No |
| I66..21 | Occlusion and stenosis of right posterior cerebral artery | Yes |
| I66..22 | Occlusion and stenosis of left posterior cerebral artery | Yes |
| I66..23 | Occlusion and stenosis of bilateral posterior cerebral arteries | Yes |
| I66..29 | Occlusion and stenosis of unspecified posterior cerebral artery | Yes |
| I66..3 | Occlusion and stenosis of cerebellar arteries | Yes |
| I66..8 | Occlusion and stenosis of other cerebral arteries | Yes |
| I66..9 | Occlusion and stenosis of unspecified cerebral artery | Yes |
Last reviewed: September 2026