I65.9 ICD-10-CA code: Occlusion and stenosis of unspecified precerebral artery
I65.9 is the ICD-10-CA code for “Occlusion and stenosis of unspecified precerebral artery” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
I65.9Occlusion and stenosis of unspecified precerebral artery
Short description: Occlusion & stenosis precereb art NOS
ICD-10-CA · Canada · Also written I659
Index terms
Entries in CIHI’s alphabetical index that lead to I65.9. Searching the index by the condition the note names is how coders reach this code.
- Stricture, artery, precerebral
- Narrowing, artery NEC, precerebral
- Embolism (septic), precerebral artery
- Embolism (septic), artery, precerebral
- Occlusion, occluded, artery, precerebral
- Stenosis (cicatricial), artery NEC, precerebral
- Obstruction, obstructed, obstructive, artery, precerebral
- Thrombosis, thrombotic (multiple) (progressive) (septic) (vein) (vessel), precerebral artery
- Thrombosis, thrombotic (multiple) (progressive) (septic) (vein) (vessel), artery, arteries (postinfectional), precerebral
Notes for I65.9
As CIHI prints them, with any note I65.9 takes from the headings above it.
Includes
- Precerebral artery NOS
- embolism, narrowing, obstruction (complete)(partial), thrombosis of basilar, carotid or vertebral arteries, not resulting in cerebral infarctionFrom I65 Occlusion and stenosis of precerebral arteries, not resulting in cerebral infarction
- With mention of hypertension (conditions in I10 and I15.-)From I60-I69 Cerebrovascular diseases
Use additional code
Add a code for this detail when the note documents it.
- Use additional code from category (E10-E14) with fourth and fifth characters .52 to classify any associated diabetes mellitus.From I65 Occlusion and stenosis of precerebral arteries, not resulting in cerebral infarction
- Use additional code to identify presence of hypertension.From I60-I69 Cerebrovascular diseases
Excludes
Conditions classified elsewhere.
- When causing cerebral infarction (I63.-)From I65 Occlusion and stenosis of precerebral arteries, not resulting in cerebral infarction
- Transient cerebral ischaemic attacks and related syndromes (G45.-)traumatic intracranial haemorrhage (S06.-)vascular dementia (F01.-)From I60-I69 Cerebrovascular diseases
- Certain:• conditions originating in the perinatal period (P00-P96)• infectious and parasitic diseases (A00-B99)complications of pregnancy, childbirth and the puerperium (O00-O99)congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)endocrine, nutritional and metabolic diseases (E00-E90)injury, poisoning and certain other consequences of external causes (S00-T98)neoplasms (C00-D48)symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)systemic connective tissue disorders (M30-M36)transient cerebral ischaemic attacks and related syndromes (G45.-)From Chapter 9: Diseases of the circulatory system (I00-I99)
Where I65.9 sits
- 1ChapterChapter 9: Diseases of the circulatory system (I00-I99)
- 2Block I60-I69Cerebrovascular diseases
- 3Category I65Occlusion and stenosis of precerebral arteries, not resulting in cerebral infarction
- 4Valid code I65.9Occlusion and stenosis of unspecified precerebral artery
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does ICD-10-CA code I65.9 mean?
I65.9 is the ICD-10-CA code for “Occlusion and stenosis of unspecified precerebral artery” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is I65.9 in ICD-10-CA?
I65.9 sits under I65 Occlusion and stenosis of precerebral arteries, not resulting in cerebral infarction, within I60-I69 Cerebrovascular diseases, within Chapter 9: Diseases of the circulatory system (I00-I99).
What coding notes apply to I65.9?
ICD-10-CA lists Includes, Use additional code, Excludes notes for I65.9, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.