2027 ICD-10-CM Diagnosis Code I63.9Cerebral infarction, unspecified
ICD-10-CM Codes›I00–I99›I60-I69›I63
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 249
- Chronic Condition
I63.9 is a billable ICD-10-CM diagnosis code for cerebral infarction, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 23 through 24, 61 through 66, 791, 793. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 84 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Cerebral infarction.
For Medicare Advantage risk adjustment, I63.9 maps to CMS-HCC Category 249 (Ischemic or Unspecified Stroke) under the V28 model, adding a risk factor of about 0.239 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
I63.9 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute symptomatic epileptic seizure due to cerebrovascular accident
- Autosomal recessive leukoencephalopathy, ischemic stroke, retinitis pigmentosa syndrome
- Brainstem stroke syndrome
- Cerebellar infarction
- Cerebellar stroke
- Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy
- Cerebral infarction
- Cerebrovascular accident
- Cerebrovascular accident during operation on heart
- Cerebrovascular accident following heart procedure
- Cerebrovascular accident of basal ganglia
- Cerebrovascular accident of brainstem
- Cerebrovascular accident of medulla oblongata
- Cerebrovascular accident with intracranial hemorrhage
- Cerebrovascular disorder in the puerperium
- Chorea due to injury of head
- Completed stroke
- Cryptogenic stroke
- CVA during surgery
- Dementia due to hemorrhagic cerebral infarction due to hypertension
- Diffuse cerebrovascular disease
- Epilepsy due to cerebrovascular accident
- Extension of cerebrovascular accident
- Hemichorea
- Hemichorea due to cerebral infarction
- Hemichorea due to head injury
- Hemorrhagic cerebral infarction
- Hemorrhagic cerebral infarction due to hypertension
- Hemorrhagic infarction
- Iatrogenic ischemic cerebral infarction
- Infarction of visual cortex
- Ischemic stroke
- Ischemic stroke without coma
- Ischemic stroke without residual deficits
- Left sided cerebral hemisphere cerebrovascular accident
- Livedo racemosa
- Multi-infarct dementia
- Multi-infarct dementia with delirium
- Multi-infarct dementia with delusions
- Multi-infarct dementia with depression
- Multi-infarct dementia, uncomplicated
- Nonparalytic stroke
- Occlusive stroke
- Pediatric arterial ischemic stroke
- Posterior cerebral circulation infarction
- Posterior inferior cerebellar artery syndrome
- Progressing stroke
- R.I.N.D. syndrome
- Silent cerebral infarct
- Sneddon syndrome
- Stroke co-occurrent with migraine
- Stroke in the puerperium
- Stroke of uncertain pathology
- Thrombotic stroke
- White matter disorder co-occurrent and due to cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to I63.9: its own notes plus those printed at I63, block I60-I69, and Chapter 9. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- occlusion and stenosis of cerebral and precerebral arteries, resulting in cerebral infarction
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Stroke NOS
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- traumatic intracranial hemorrhage (S06.-)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- transient cerebral ischemic attacks and related syndromes (G45.-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
- systemic connective tissue disorders (M30-M36)
- transient cerebral ischemic attacks and related syndromes (G45.-)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name I63.9, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming I63.9: they are not reported together with it, unless the two conditions are unrelated.
Code First 2
These codes say to code first a condition named in the note, and I63.9 is one of the conditions named.
- R29.7 National Institutes of Health Stroke Scale (NIHSS) scorethe type of cerebral infarction (I60.-, I61.-, I62.-, I63.-) names I63.-, which includes this code
- Z92.82 Status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facilityacute cerebral infarction (I63.-) names I63.-, which includes this code
Code Also 11
These codes say I63.9 may also be needed to fully describe the condition. The note gives no sequencing direction.
- D57.03 Hb-SS disease with cerebral vascular involvementif applicable, cerebral infarction (I63.-) names I63.-, which includes this code
- D57.213 Sickle-cell/Hb-C disease with cerebral vascular involvementif applicable, cerebral infarction (I63.-) names I63.-, which includes this code
- D57.413 Sickle-cell thalassemia, unspecified, with cerebral vascular involvementif applicable cerebral infarction (I63.-) names I63.-, which includes this code
- D57.433 Sickle-cell thalassemia beta zero with cerebral vascular involvementif applicable cerebral infarction (I63.-) names I63.-, which includes this code
- D57.453 Sickle-cell thalassemia beta plus with cerebral vascular involvementif applicable cerebral infarction (I63.-) names I63.-, which includes this code
- D57.813 Other sickle-cell disorders with cerebral vascular involvementif applicable: cerebral infarction (I63.-) names I63.-, which includes this code
- D81.32 Adenosine deaminase 2 deficiencystroke (I63.-) names I63.-, which includes this code
- G43.6 Persistent migraine aura with cerebral infarctionthe type of cerebral infarction (I63.-) names I63.-, which includes this code
- G96.81 Intracranial hypotensionStroke (I63.-) names I63.-, which includes this code
- I16.1 Hypertensive emergencycerebral infarction (I63.-) names I63.-, which includes this code
- I67.850 Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathystroke (I63.-) names I63.-, which includes this code
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
cerebrovascular (ischemic) I63.9
aborted I63.9
craniovascular I63.9
vascular, brain I63.9
Deficit See Also: Deficiency;
cerebral (acute) See Also: Occlusion, artery cerebral or precerebral, with infarction; I63.9
Stroke (apoplectic) (brain) (ischemic) (paralytic) I63.9
cryptogenic See Also: infarction, cerebral; I63.9
in evolution I63.9
unspecified (NOS) I63.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Cerebral Infarction
the formation of an area of necrosis in the cerebrum caused by an insufficiency of arterial or venous blood flow. infarcts of the cerebrum are generally classified by hemisphere (i.e., left vs. right), lobe (e.g., frontal lobe infarction), arterial distribution (e.g., infarction, anterior cerebral artery), and etiology (e.g., embolic infarction).
Patient EducationClinical
Ischemic Stroke
A stroke happens when there is a loss of blood flow to part of the brain. Your brain cells cannot get the oxygen and nutrients they need from blood, and they start to die within a few minutes. This can cause lasting brain damage, long-term disability, or even death.
The full article covers:
- What is an ischemic stroke?
- What causes an ischemic stroke?
- What are the symptoms of ischemic stroke?
- How is an ischemic stroke diagnosed?
- How is an ischemic stroke treated?
- Can an ischemic stroke be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert I63.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About I63.9Overview
What is the ICD-10 code for cerebral infarction, unspecified?
The ICD-10-CM code for cerebral infarction, unspecified is I63.9 (sometimes written as I639). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is I63.9 (Cerebral infarction) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report cerebral infarction, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does I63.9 group to?
When cerebral infarction, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 24, 64, 23, 65, 61, 62, 63, 66, with relative weights from 0.6770 to 5.7422 depending on complications. Higher weights mean higher Medicare reimbursement.
Is I63.9 a CC or MCC?
CMS lists I63.9 as an MCC (major complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 84 closely related codes in its exclusion list.
Can I63.9 be reported with a code from P91.82?
Not as a rule. The Excludes1 note at I63, which applies to I63.9, lists "neonatal cerebral infarction (P91.82-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is I63.9?
I63.9 (cerebral infarction, unspecified) maps to CMS-HCC Category 249 (Ischemic or Unspecified Stroke), commonly written as HCC 249, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 100 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.
Does I63.9 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, I63.9 adds a risk adjustment factor of about 0.239 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.081 to 0.377 depending on the payment segment). A more severe related category (HCC 248) supersedes it when both are reported. See the full factor table on the HCC 249 category page.
