I66.3 — Occlusion and stenosis of cerebellar arteries
I66.3 is a billable, specific ICD-10-CM code for occlusion and stenosis of cerebellar arteries. It is valid for submission on a claim.
Risk adjustment
I66.3 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
I66.3 is named in 51 Medicare coverage policies — 51 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)
- A52992Billing and Coding: Non-Invasive Cerebrovascular Arterial Studies
- A52992Billing and Coding: Non-Invasive Cerebrovascular Arterial Studies
- A56423Billing and Coding: Cardiology Non-emergent Outpatient Stress Testing
How I66.3 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to I66.3.
- Thrombosis, thrombotic›cerebellar artery(anterior inferior) (posterior inferior) (superior)
- Embolism›artery›cerebellar(anterior inferior) (posterior inferior) (superior)
- Occlusion, occluded›artery›cerebellar(anterior inferior) (posterior inferior) (superior)
Related codes at this level
Codes that share I66. If I66.3 is not quite right, the correct code is usually one of these.
Questions about I66.3
- Is I66.3 a billable ICD-10-CM code?
- Yes. I66.3 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does I66.3 sit in the tabular list?
- Diseases of the circulatory system (I00-I99), in the block Cerebrovascular diseases (I60-I69).