Crystal's MCW Coder Hub🧬 ICD-10 CM I63.411 - Cerebral Infarction Due to Embolism of Right Middle Cerebral Artery
Quick Reference
Full Name: Cerebral infarction due to embolism of right middle cerebral artery Code Type: ICD-10-CM | Billable: ✅ Yes | Valid FY2026: ✅ Yes Chapter: Diseases of the Circulatory System (I00-I99) HCC V28: HCC 96 - Ischemic or Unspecified Stroke POA Indicator: Required on inpatient claims
🧠 Clinical Description
ICD-10 CM I63.411 identifies a cerebral infarction — the death of brain tissue due to insufficient blood supply — that is specifically caused by an embolism (a clot or foreign material that has traveled through the bloodstream) occluding the right middle cerebral artery (MCA). The MCA is the largest of the three major cerebral arteries and the most commonly affected vessel in ischemic stroke. It arises from the internal carotid artery and supplies the majority of the lateral (outer) surface of the cerebral hemisphere, including primary motor cortex, primary sensory cortex, Broca’s area (dominant hemisphere), Wernicke’s area (dominant hemisphere), and portions of the optic radiations.
Right MCA Territory: What is Affected?
The right MCA supplies the right hemisphere, which governs:
- Left-sided motor and sensory function (contralateral control)
- Visuospatial processing and attention
- Left homonymous hemianopia (visual field cut)
- Prosody (the rhythm and intonation of speech)
- Left hemispatial neglect (failure to attend to the left side of space)
Because this code specifies the right MCA in a non-dominant hemisphere (in most right-handed individuals), patients typically present with left-sided hemiplegia or hemiparesis, left facial droop, left hemispatial neglect, and constructional apraxia, but are generally spared frank aphasia (which is a dominant, typically left hemisphere, function). WHO ICD-10-CM FY2026
What is an Embolism in This Context?
An embolism differs from a thrombosis in its source and mechanism:
- Embolism (I63.411): A clot or debris formed elsewhere (commonly the heart in atrial fibrillation, or proximal vessels) that travels through the bloodstream and lodges in the MCA.
- Thrombosis (I63.311): A clot that forms in situ within the MCA itself, usually due to atherosclerotic plaque rupture.
The distinction is clinically and coding-wise significant. If the provider documents “embolic stroke,” “cardioembolic stroke,” or “embolism of the MCA,” I63.411 is appropriate. AHA Coding Clinic
📋 Code Details
| Field | Detail |
|---|---|
| Code | I63.411 |
| Full Description | Cerebral infarction due to embolism of right middle cerebral artery |
| Code Type | ICD-10-CM Diagnosis |
| Billable / Specific | ✅ Yes - Highest specificity available for this condition |
| Valid FY2026 | ✅ Yes |
| POA Indicator Required | ✅ Yes - Required on inpatient UB-04 claims |
| MCC Status | This code can serve as a CC/MCC trigger depending on comorbid conditions; see DRG section |
| Gender Edits | None |
| Age Edits | Not applicable to neonates (see Excludes1 below) |
🌲 Code Tree (Hierarchy)
I00-I99 Diseases of the Circulatory System
└── I60-I69 Cerebrovascular Diseases
└── I63 Cerebral Infarction
└── I63.4 Cerebral infarction due to embolism of cerebral arteries
└── I63.41 Cerebral infarction due to embolism of middle cerebral artery
├── I63.411 ← RIGHT middle cerebral artery ✅ (YOU ARE HERE)
├── I63.412Left middle cerebral artery
├── I63.413 Bilateral middle cerebral arteries
└── I63.419 Unspecified middle cerebral artery
Sibling Codes at the I63.4 Level (Embolism of Cerebral Arteries)
| Code | Description |
|---|---|
| I63.40 | Embolism of unspecified cerebral artery |
| I63.41x | Embolism of middle cerebral artery (parent of I63.411) |
| I63.42x | Embolism of anterior cerebral artery |
| I63.43x | Embolism of posterior cerebral artery |
| I63.44x | Embolism of cerebellar artery |
| I63.49 | Embolism of other cerebral artery |
✅ Includes
At the I63 category level, the following conditions are included under cerebral infarction codes: CMS ICD-10-CM FY2026 Tabular List
- Occlusion and stenosis of cerebral and precerebral arteries resulting in cerebral infarction
Key Point
The distinction is the resultant infarction. If occlusion or stenosis does NOT result in infarction, refer to category I66.- (occlusion/stenosis of cerebral arteries without infarction) instead.
🚫 Excludes
Excludes 1 (Cannot be coded together with I63.411)
| Code | Description |
|---|---|
| P91.82- | Neonatal cerebral infarction |
Excludes 1 Reminder
Excludes 1 means these codes cannot be used together with I63.411. If the patient is a neonate with cerebral infarction, use P91.82- instead.
Excludes 2 (Not included in this code but may be coded together when applicable)
| Code | Description |
|---|---|
| Z86.73 | Personal history of cerebral infarction without residual deficits (chronic, sequelae-free) |
| I69.3- | Sequelae of cerebral infarction (residual deficits from a prior stroke) |
Excludes 2 Clarification
📌 Use Additional Code Guidance
| Additional Code | Description | When to Use |
|---|---|---|
| R29.7- | NIHSS (National Institutes of Health Stroke Scale) score | Whenever NIHSS is documented in the medical record |
| I48.- | Atrial fibrillation and flutter | If documented as the embolic source |
| I21.- | Acute myocardial infarction | If cardiac embolism is related to MI |
| I35.- / I34.- | Valvular heart disease | If embolic source is valvular |
| Z82.3 | Family history of stroke | Per clinical discretion |
NIHSS Coding Tip
The NIHSS score (R29.7-) is an instructional note at the I63 category level and should always be coded as an additional code when documented. This is a significant risk adjustment and quality metric opportunity. NIHSS scores range from 0 (no deficit) to 42 (severe). The 7th digit specifies the score:
🏥 MS-DRG Assignment
ICD-10 CM I63.411 falls under MDC 01 - Diseases and Disorders of the Nervous System. DRG assignment depends on two primary factors: (1) whether thrombolytic (tPA) therapy was administered and (2) the presence of a Major Complication/Comorbidity (MCC) or Complication/Comorbidity (CC). CMS MS-DRG v37.0 Definitions Manual
With Thrombolytic Agent (tPA Administered)
| MCC | CC | DRG | Title |
|---|---|---|---|
| ✅ Yes | — | DRG 061 | Ischemic Stroke, Precerebral Occlusion or TIA with Thrombolytic Agent with MCC |
| ❌ No | ✅ Yes | DRG 062 | Ischemic Stroke, Precerebral Occlusion or TIA with Thrombolytic Agent with CC |
| ❌ No | ❌ No | DRG 063 | Ischemic Stroke, Precerebral Occlusion or TIA with Thrombolytic Agent without CC/MCC |
Without Thrombolytic Agent
| MCC | CC | DRG | Title |
|---|---|---|---|
| ✅ Yes | — | DRG 064 | Intracranial Hemorrhage or Cerebral Infarction with MCC |
| ❌ No | ✅ Yes | DRG 065 | Intracranial Hemorrhage or Cerebral Infarction with CC or tPA in 24 hours |
| ❌ No | ❌ No | DRG 066 | Intracranial Hemorrhage or Cerebral Infarction without CC/MCC |
DRG Optimization Note
MCCs in stroke cases commonly include: respiratory failure, mechanical ventilation, septicemia, coma, or acute renal failure. CCs commonly include: pneumonia, urinary tract infection, dysphagia, hemiplegia (coded from I69.35- for chronic, or as a sequela), and atrial fibrillation. Accurate documentation and capture of all comorbidities significantly impacts DRG weight and reimbursement.
📊 HCC Risk Adjustment
ICD-10 CM I63.411 is an HCC-mapped diagnosis, meaning it contributes to Medicare Advantage risk adjustment scores. CMS-HCC Model V28 Final Rule
| HCC Model | HCC # | HCC Label | Approx. RAF (Community Non-Dual Aged) |
|---|---|---|---|
| CMS-HCC V24 | HCC 100 | Ischemic or Unspecified Stroke | ~0.321 |
| CMS-HCC V28 | HCC 96 | Ischemic or Unspecified Stroke | ~0.299 |
HCC Capture Guidelines
- HCC codes must be documented, diagnosed, and managed during the encounter — not just historical
- Stroke (I63.-) must be coded as active during the encounter to capture the HCC; once resolved, the sequela code (I69.3-) or history code (Z86.73) would apply instead
- V28 was fully phased in as of CY2025 (100% V28); always verify RAF scores against the CMS finalized model coefficients table for the applicable benefit year
- Hierarchical rules: HCC 96 is hierarchical with less severe cerebrovascular HCCs (e.g., TIA, late effects of stroke), meaning only the highest HCC in the hierarchy will be counted
💊 wRVU & Assistant Payable
Not Applicable to Diagnosis Codes
wRVU (Work Relative Value Unit) is a CPT procedure-based metric and does not apply to ICD-10-CM diagnosis codes. The wRVU is assigned to the evaluation and management (E/M) or procedural CPT codes reported alongside I63.411.
Assistant Payable is a CPT surgical modifier concept indicating whether a surgical assistant may bill for a procedure. It is not applicable to diagnosis codes.
Commonly Associated CPT Codes for Acute Stroke Encounters
| CPT Code | Description | Context |
|---|---|---|
| 99223 | Initial hospital care, high complexity | Admission H&P for acute stroke |
| 99233 | Subsequent hospital care, high complexity | Daily rounding, complex medical decision-making |
| 99239 | Hospital discharge >30 minutes | Discharge day management |
| 99253 | Inpatient consult, moderate complexity | Neurology or neurosurgery consult |
| 99255 | Inpatient consult, high complexity | Neurology consult with complex MDM |
| 99291 | Critical care, first 30-74 minutes | ICU level care for severe stroke |
| 70553 | MRI brain with and without contrast | Brain MRI for stroke workup |
| 70558 | MRI angiography, brain with contrast | MRA for vascular anatomy |
| 93886 | Transcranial Doppler (TCD), complete | Vascular flow study |
| 93880 | Carotid duplex scan, bilateral | Carotid source evaluation |
Relevant Modifiers for Inpatient Profee Billing
| Modifier | Description | Use Case |
|---|---|---|
| -AI | Principal Physician of Record | Attending of record on admission (Medicare) |
| -GC | Teaching physician supervising resident | Teaching hospital scenarios |
| -GE | Resident without direct supervision | Primary care exception teaching settings |
| -25 | Significant, separately identifiable E/M same day as procedure | E/M billed same day as a procedure |
| -59 | Distinct procedural service | Separate and distinct procedure |
🌿 Related / Commonly Paired ICD-10-CM Codes
| Code | Description | Relationship |
|---|---|---|
| I48.0-I48.19 | Atrial fibrillation | Common embolic source; code additionally |
| R29.7- | NIHSS Score | Use additional code per instructional note |
| I69.351 | Hemiplegia/hemiparesis following cerebral infarction, dominant side | Sequela code if chronic deficits remain |
| I69.354 | Hemiplegia/hemiparesis following cerebral infarction, non-dominant side | Common with right MCA involvement (left side deficits) |
| I69.391 | Aphasia following cerebral infarction | Less common with right MCA, but possible |
| I69.398 | Other sequelae of cerebral infarction | Unspecified residual deficits |
| Z86.73 | Personal history of cerebral infarction without residual deficit | Prior stroke, resolved |
| I66.01 | Occlusion and stenosis of right middle cerebral artery | Without resultant infarction |
| G46.0 | Middle cerebral artery syndrome | Functional syndrome; do not use instead of I63.411 when infarction is confirmed |
| I63.412 | Cerebral infarction due to embolism of LEFT middle cerebral artery | Contralateral equivalent |
| I63.311 | Cerebral infarction due to thrombosis of right middle cerebral artery | Same vessel, different mechanism |
📝 Coding Examples
Example 1: Acute Embolic Stroke, Afib Source, No tPA, NIHSS Documented
A 72-year-old male with known persistent atrial fibrillation presents to the ED with sudden onset left-sided weakness, left facial droop, and left hemispatial neglect. MRI DWI confirms acute right MCA territory infarction. NIHSS score documented as 12. tPA was not administered due to late presentation. Provider documents: “Acute ischemic stroke due to embolism, right middle cerebral artery territory. Cardioembolic source likely given known Afib.”
Codes:
- I63.411 - Cerebral infarction due to embolism of right middle cerebral artery (principal)
- I48.19 - Other persistent atrial fibrillation (additional - embolic source)
- R29.712 - NIHSS score 12 (additional - per instructional note)
DRG: DRG 065 or 064 depending on presence of additional CC/MCC
Example 2: Right MCA Embolic Stroke with tPA and Respiratory Failure (MCC)
A 68-year-old female is admitted with acute onset right-sided facial droop and left hemiplegia. MRI confirms right MCA embolic infarction. tPA (alteplase) was administered within 3 hours of symptom onset. Patient subsequently developed aspiration pneumonia with acute hypoxic respiratory failure requiring intubation.
Codes:
- I63.411 - Right MCA embolic cerebral infarction (principal)
- J96.01 - Acute respiratory failure with hypoxia (MCC — additional)
- J18.9 - Aspiration pneumonia (CC — additional)
- R29.720 - NIHSS score (document specific value) (additional)
DRG: DRG 061 - Ischemic Stroke with Thrombolytic Agent with MCC
Example 3: Sequela Encounter — Do NOT Use I63.411
Patient presents for outpatient PT follow-up 6 months after right MCA embolic stroke. They have residual left hemiparesis affecting the non-dominant side.
Correct Codes:
- I69.354 - Hemiplegia/hemiparesis following cerebral infarction, affecting non-dominant side (principal)
- Z86.73 is NOT used here since there ARE residual deficits
Do NOT Code I63.411 for Old Strokes
I63.411 is reserved for the acute/current cerebral infarction. Once the patient is in the chronic/recovery phase with residual deficits, the I69.3- sequela codes are appropriate. The Excludes 2 note at I63 confirms this distinction.
Example 4: Occlusion Without Infarction — Do NOT Use I63.411
Patient has right MCA occlusion identified on imaging but no infarction confirmed — TIA presentation, symptoms resolved within 24 hours.
Correct Code:
- I66.01 - Occlusion and stenosis of right middle cerebral artery (without infarction)
- G45.9 - TIA, unspecified (if TIA is documented)
Key Distinction
📌 Documentation Tips for Providers
The following documentation elements are critical for accurate coding and optimal DRG/HCC capture:
- Specify the mechanism - Document “embolic,” “thrombotic,” or “due to atrial fibrillation” as applicable; this drives the 4th digit selection (I63.4- vs I63.3-)
- Specify laterality - Document “right” or “left” MCA to support the 6th digit (411 vs 412)
- Document NIHSS score - This allows capture of R29.7- additional codes; required for stroke quality measures
- Document tPA/alteplase administration - This drives DRG 061-063 vs 064-066, significantly impacting reimbursement
- Document all complications - Aspiration pneumonia, dysphagia, respiratory failure, and UTI all serve as CC/MCC and elevate DRG weight
- Identify embolic source - “Cardioembolic due to atrial fibrillation” vs “cryptogenic” affects additional code assignment
- Clarify acuity - “Acute,” “subacute,” or “chronic” stroke with or without residual deficits determines I63.- vs I69.3- vs Z86.73
🔗 Coding Guidelines Reference
Per the ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.9 (Diseases of the Circulatory System): ICD-10-CM Official Guidelines FY2026
- Cerebral infarction codes (I63.-) should be sequenced as the principal diagnosis for acute infarction encounters
- When the cause of the embolism is documented (e.g., atrial fibrillation), an additional code for the underlying cause should be assigned
- Sequelae codes (I69.3-) are assigned for any time after the acute phase when residual deficits are present
- The POA indicator is critical for inpatient claims; stroke coded as “not present on admission” may trigger quality/penalty flags under HAC policies
Sources: CMS ICD-10-CM FY2026 Tabular List and Official Guidelines; CMS MS-DRG v37.0 Definitions Manual; CMS-HCC Model V28 Final Announcement (CY2024/2025); AHA ICD-10-CM/PCS Coding Clinic; WHO ICD-10 Classification of Diseases; AAPC ICD-10-CM Code Reference; NIH NIHSS Documentation Standards