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I65.9

I65.9Occlusion and stenosis of unspecified precerebral artery

Billable / specific codeICD-10-CM

I65.9 is a billable, specific ICD-10-CM code for occlusion and stenosis of unspecified precerebral artery. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Occlusion and stenosis of precerebral artery NOS

Risk adjustment

I65.9 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

I65.9 is named in 12 Medicare coverage policies 12 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56551Billing and Coding: Visual Fields Testing
  • A56697Billing and Coding: Non-Invasive Vascular Studies
  • A56697Billing and Coding: Non-Invasive Vascular Studies
  • A56722Billing and Coding: Intraoperative Neurophysiological Testing

How I65.9 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 I65.9.

  • Occlusion, occludedarteryprecerebral

Related codes at this level

Codes that share I65. If I65.9 is not quite right, the correct code is usually one of these.

Questions about I65.9

Is I65.9 a billable ICD-10-CM code?
Yes. I65.9 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does I65.9 sit in the tabular list?
Diseases of the circulatory system (I00-I99), in the block Cerebrovascular diseases (I60-I69).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.