I65.8
BillableOcclusion and stenosis of other precerebral arteries
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is I65.8 an HCC code?
No. I65.8 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
I65.8 is the ICD-10-CM diagnosis code for occlusion and stenosis of other precerebral arteries. A narrowing or blockage of blood vessels in the neck that supply the brain, other than the vertebral, basilar, or carotid arteries. I65.8 sits in the ICD-10-CM chapter for diseases of the circulatory system (i00-i99), within the section covering cerebrovascular diseases (i60-i69).
I65.8 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
This is a catch-all code for less common precerebral arteries; document the specific artery name in the medical record for clarity.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for I65.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a catch-all code for less common precerebral arteries; document the specific artery name in the medical record for clarity
- •Ensure the affected artery is truly precerebral (supplying the brain) and not intracranial before assigning this code