I63.549 Cerebral infarction due to unspecified occlusion or stenosis of unspecified cerebellar artery

Billable ICD-10-CM code, FY2026. Acts as a Major Complication or Comorbidity (MCC) as a secondary diagnosis.

Applies from I63 Cerebral infarction

Includes

• occlusion and stenosis of cerebral and precerebral arteries, resulting in cerebral infarction

Excludes1 (never code together)

• neonatal cerebral infarction (P91.82-)

Excludes2 (not included here)

• chronic, without residual deficits (sequelae) (Z86.73)
• sequelae of cerebral infarction (I69.3-)

Use additional code

• code, if applicable, to identify status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facility (Z92.82)
• code, if known, to indicate National Institutes of Health Stroke Scale (NIHSS) score (R29.7-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 249 — Ischemic or Unspecified Stroke
• CMS-HCC V22: HCC 100 — Ischemic or Unspecified Stroke
• ESRD V24: HCC 100

MS-DRG index

Defines the logic of DRG(s) 023-024 in MDC 01.

Approximate ICD-9-CM (GEMs)

• 434.91 Cerebral artery occlusion, unspecified with cerebral infarction (approximate)

Code annotations containing back-references to I63.549

Back-references to I63.5

• Type 1 Excludes: I66 Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction ("Occlusion and stenosis of cerebral artery causing cerebral infarction (I63.3-I63.5)")
• Type 1 Excludes: I67 Other cerebrovascular diseases ("Occlusion and stenosis of cerebral artery causing cerebral infarction (I63.3-I63.5-)")
• Type 2 Excludes: I74 Arterial embolism and thrombosis ("cerebral embolism and thrombosis (I63.3-I63.5, I66.-)")

Back-references to I63

• Code Also: D57.03 Hb-SS disease with cerebral vascular involvement (", if applicable, cerebral infarction (I63.-)")
• Code Also: D57.213 Sickle-cell/Hb-C disease with cerebral vascular involvement (", if applicable, cerebral infarction (I63.-)")
• Code Also: D57.413 Sickle-cell thalassemia, unspecified, with cerebral vascular involvement (", if applicable cerebral infarction (I63.-)")
• Code Also: D57.433 Sickle-cell thalassemia beta zero with cerebral vascular involvement (", if applicable cerebral infarction (I63.-)")
• Code Also: D57.453 Sickle-cell thalassemia beta plus with cerebral vascular involvement (", if applicable cerebral infarction (I63.-)")
• Code Also: D57.813 Other sickle-cell disorders with cerebral vascular involvement (", if applicable: cerebral infarction (I63.-)")
• Code Also: D81.32 Adenosine deaminase 2 deficiency ("stroke (I63.-)")
• Type 1 Excludes: G31.84 Mild cognitive impairment of uncertain or unknown etiology ("cerebrovascular diseases (I60-I69)")
• Code Also: G43.6 Persistent migraine aura with cerebral infarction ("the type of cerebral infarction (I63.-)")
• Code First: G46 Vascular syndromes of brain in cerebrovascular diseases ("underlying cerebrovascular disease (I60-I69)")
• Code Also: G96.81 Intracranial hypotension ("Stroke (I63.-)")
• Type 2 Excludes: I10 Essential (primary) hypertension ("essential (primary) hypertension involving vessels of brain (I60-I69)")
• Type 2 Excludes: I15 Secondary hypertension ("secondary hypertension involving vessels of brain (I60-I69)")
• Use Additional: I16.1 Hypertensive emergency ("cerebral infarction (I63.-)")
• Code Also: I67.850 Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy ("stroke (I63.-)")
• Type 1 Excludes: P91.82 Neonatal cerebral infarction ("cerebral infarction (I63.-)")
• Code First: R29.7 National Institutes of Health Stroke Scale (NIHSS) score ("the type of cerebral infarction (I63.-)")
• Code First: Z92.82 Status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facility ("acute cerebral infarction (I63.-)")

Nearby codes

• I63.539 Cerebral infarction due to unspecified occlusion or stenosis of unspecified posterior cerebral artery
• I63.54 Cerebral infarction due to unspecified occlusion or stenosis of cerebellar artery
• I63.541 Cerebral infarction due to unspecified occlusion or stenosis of right cerebellar artery
• I63.542 Cerebral infarction due to unspecified occlusion or stenosis of left cerebellar artery
• I63.543 Cerebral infarction due to unspecified occlusion or stenosis of bilateral cerebellar arteries
• I63.549 Cerebral infarction due to unspecified occlusion or stenosis of unspecified cerebellar artery (this code)
• I63.59 Cerebral infarction due to unspecified occlusion or stenosis of other cerebral artery
• I63.6 Cerebral infarction due to cerebral venous thrombosis, nonpyogenic
• I63.8 Other cerebral infarction
• I63.81 Other cerebral infarction due to occlusion or stenosis of small artery
• I63.89 Other cerebral infarction