I66.09
I66.09 — Occlusion and stenosis of unspecified middle cerebral artery
Billable / specific codeICD-10-CM
I66.09 is a billable, specific ICD-10-CM code for occlusion and stenosis of unspecified middle cerebral artery. It is valid for submission on a claim.
Risk adjustment
I66.09 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
I66.09 is named in 9 Medicare coverage policies — 9 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A52868Billing and Coding: Transesophageal Echocardiography (TEE)
- A56722Billing and Coding: Intraoperative Neurophysiological Testing
- A56781Billing and Coding: Transthoracic Echocardiography (TTE)
- A57174Billing and Coding: MolDX: Pharmacogenomics Testing
Related codes at this level
Codes that share I66.0. If I66.09 is not quite right, the correct code is usually one of these.
Questions about I66.09
- Is I66.09 a billable ICD-10-CM code?
- Yes. I66.09 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does I66.09 sit in the tabular list?
- Diseases of the circulatory system (I00-I99), in the block Cerebrovascular diseases (I60-I69).