🧬 ICD-10 CM I61.0 — Nontraumatic Intracerebral Hemorrhage In Hemisphere, Subcortical
Billable Code Confirmed
ICD-10 CM I61.0 is a complete 4-character code requiring no further subdivision, making it fully billable for inpatient reporting. The fourth character “0” specifies the subcortical location within the cerebral hemisphere, distinguishing it from cortical, multiple, or unspecified hemispheric hemorrhages. This level of anatomical detail is achievable through standard neuroimaging (CT or MRI) and is typically well-documented by neurology or neurosurgery. No 7th character extension applies to this code category, unlike injury codes.
Non-Billable Parent Codes
I61 — Nontraumatic intracerebral hemorrhage is the category-level parent and cannot be used alone; it requires a fourth character to specify the anatomical site of the hemorrhage (subcortical, cortical, brainstem, cerebellum, etc.). I60-I69 — Cerebrovascular diseases is the block-level grouping and is never directly assignable; it exists only to organize the more specific category and subcategory codes beneath it.
Clinical Context
The distinction between subcortical and cortical (lobar) intracerebral hemorrhage is clinically significant because the two have different underlying etiologies. Subcortical hemorrhages, particularly in the basal ganglia, thalamus, and internal capsule, are most commonly associated with chronic hypertension and small vessel disease. Cortical (lobar) hemorrhages, by contrast, are more frequently associated with cerebral amyloid angiopathy, especially in elderly patients. Accurate location coding therefore reflects both the anatomical findings on imaging and the likely underlying disease process driving the bleed.
Code Classification
ICD-10 CM I61.0 is a diagnosis code used to report the occurrence of a nontraumatic, spontaneous intracerebral hemorrhage located in the subcortical region of a cerebral hemisphere. It is not a procedure code and carries no inherent laterality character, meaning it does not distinguish between right and left hemisphere involvement at this level of granularity.
🔍 Code Description
Nontraumatic intracerebral hemorrhage in the subcortical hemisphere represents a spontaneous bleed occurring deep within the brain tissue, most commonly involving structures such as the basal ganglia, thalamus, or internal capsule, rather than the outer cortical surface. This type of hemorrhagic stroke is most frequently the result of long-standing, poorly controlled hypertension, which causes degeneration of small penetrating arteries (lipohyalinosis) that eventually rupture under pressure. Clinical presentation often includes sudden-onset contralateral hemiparesis or hemiplegia, sensory deficits, and depending on the size and location of the hematoma, varying degrees of altered consciousness. Coders should review CT or MRI reports closely, as radiology documentation often uses anatomical terms like “basal ganglia,” “thalamic,” “putaminal,” or “internal capsule” hemorrhage, all of which map to the subcortical designation under I61.0.
In the inpatient setting, I61.0 is frequently the principal diagnosis for admissions involving acute hemorrhagic stroke, and its sequencing drives MS-DRG assignment under MDC 01. Documentation supporting this code should include the imaging findings confirming subcortical location, the suspected or confirmed etiology (most often hypertensive), and any associated neurological deficits such as hemiplegia or aphasia, which should be captured with additional codes from G81.94 or R47.01 respectively. Clinicians may also document interventions such as blood pressure management protocols, osmotic therapy for cerebral edema, or surgical evacuation, all of which support the medical necessity and severity of the inpatient stay when this diagnosis is principal.
🌳 Code Tree / Hierarchy
I61 Nontraumatic intracerebral hemorrhage ❌ Non-billable
│
├── I61.0 Nontraumatic intracerebral hemorrhage in hemisphere, subcortical ◀ THIS CODE ✅ Billable
├── I61.1 Nontraumatic intracerebral hemorrhage in hemisphere, cortical ✅ Billable
├── I61.2 Nontraumatic intracerebral hemorrhage in hemisphere, unspecified ✅ Billable
│
├── I61.3 Nontraumatic intracerebral hemorrhage in brain stem ✅ Billable
├── I61.4 Nontraumatic intracerebral hemorrhage in cerebellum ✅ Billable
├── I61.5 Nontraumatic intracerebral hemorrhage, intraventricular ✅ Billable
│
├── I61.6 Nontraumatic intracerebral hemorrhage, multiple localized ✅ Billable
├── I61.8 Other nontraumatic intracerebral hemorrhage ✅ Billable
└── I61.9 Nontraumatic intracerebral hemorrhage, unspecified ✅ BillableSubcortical vs. Unspecified Coding
Tip
Subcortical hemorrhages are the most common subtype of hypertensive ICH, so this code should be anticipated frequently in inpatient stroke and neuro ICU populations; always cross-check imaging impression language against the I61 subcategory definitions before assigning I61.9.
✅ Includes
- Hemorrhage originating in the basal ganglia secondary to chronic hypertension.
- Thalamic hemorrhage confirmed via CT or MRI as located within the deep gray matter structures.
- Putaminal hemorrhage, the most common site for hypertensive subcortical bleeds.
- Internal capsule hemorrhage, often associated with significant motor pathway disruption.
- Deep white matter hemorrhage adjacent to subcortical structures when documented as such.
- Spontaneous (non-aneurysmal, non-traumatic) hematoma confined to subcortical brain tissue.
❌ Excludes
Excludes 1
ICD-10 CM I61.9 — Nontraumatic intracerebral hemorrhage, unspecified should not be reported when the medical record documents a specific subcortical location; assigning the unspecified code in the presence of specific imaging findings represents a loss of coding specificity and may understate clinical severity for DRG purposes. I61.1 — Nontraumatic intracerebral hemorrhage in hemisphere, cortical is mutually exclusive with I61.0 because the two codes represent distinct anatomical territories (deep vs. superficial brain tissue) and cannot both describe the same single hemorrhagic event.
Danger
The most common Excludes1-type error is defaulting to I61.9 when the radiology report clearly documents “basal ganglia hemorrhage” or “thalamic hemorrhage” — coders should always query the documentation for specific anatomical terminology before assigning the unspecified code, as this directly affects DRG weight and clinical accuracy.
Excludes 2
ICD-10 CM I69.1 — Sequelae of intracerebral hemorrhage may be coded separately and in addition to I61.0 when a patient is being treated for the residual effects of a prior hemorrhage (e.g., chronic hemiplegia) during an encounter that is not for the acute hemorrhagic event itself; this allows both the historical cerebrovascular disease and its lasting effects to be documented.
📋 Clinical Overview
Subcortical vs. Cortical vs. Brain Stem Hemorrhage
Differentiating the location of an intracerebral hemorrhage is essential for accurate code assignment, as the I61 category subdivides primarily by anatomical site. Subcortical hemorrhages (I61.0) involve deep gray and white matter structures and are most often hypertensive in origin, while cortical or lobar hemorrhages (I61.1) involve the outer brain surface and are more often linked to amyloid angiopathy in older adults. Brain stem hemorrhages (I61.3) carry a markedly different prognosis due to the density of vital autonomic and motor control centers in this small region. The table below summarizes key distinguishing features across these three subtypes.
| Feature | I61.0 | I61.1 | I61.3 |
|---|---|---|---|
| Typical Location | Basal ganglia, thalamus, internal capsule, and other deep gray/white matter structures of the cerebral hemisphere. | Lobar regions including frontal, parietal, temporal, or occipital cortex, often near the gray-white matter junction. | Pons, midbrain, or medulla, representing the most anatomically compact and functionally critical brain region. |
| Common Etiology | Chronic hypertension causing rupture of small penetrating arteries (lenticulostriate vessels). | Cerebral amyloid angiopathy in elderly patients, or less commonly hypertension or vascular malformations. | Hypertension is the leading cause, with hemorrhages often originating from small perforating branches of the basilar artery. |
| Typical Severity | Variable; can range from mild hemiparesis to severe deficits depending on hematoma size and extension into the ventricles. | Often presents with seizures and focal cortical deficits such as aphasia or visual field cuts depending on lobe involved. | Frequently associated with rapid deterioration, coma, and high mortality due to brain stem involvement of cardiorespiratory centers. |
Important
CDI specialists should query for “hypertensive” versus “amyloid-related” etiology when documentation is ambiguous, as this distinction can influence the assignment of additional codes for hypertensive disease (I10-I16) and impacts the overall clinical picture supporting medical necessity.
Manifestations & Symptom Burden
Hemiparesis or hemiplegia contralateral to the side of the hemorrhage is one of the most common presenting manifestations, reflecting damage to motor pathways traveling through the internal capsule. Dysarthria and aphasia may occur depending on whether the hemorrhage involves the dominant hemisphere’s language centers or their connecting white matter tracts. Altered level of consciousness, ranging from lethargy to coma, can result from mass effect, increased intracranial pressure, or extension of the hemorrhage into the ventricular system. Headache, nausea, and vomiting are frequently reported at onset due to rapidly increasing intracranial pressure. Seizures may also occur, particularly when the hemorrhage extends toward the cortical surface.
Tip
Each manifestation listed above should be evaluated for separate code assignment if it represents a clinically significant condition being actively managed during the stay — for example, G81.94 for hemiplegia, R47.01 for aphasia, or R56.9 for seizures — as these can independently affect CC/MCC status and overall DRG weight.
💰 HCC Risk Adjustment
| HCC Model | HCC Category | RAF Weight Impact | Recapture Required Annually |
|---|---|---|---|
| CMS-HCC V28 | HCC 100 — Ischemic or Unspecified Stroke (acute stroke grouping) | Moderate-to-high impact in year of diagnosis | No — acute event, not recaptured |
| CMS-HCC V24 | HCC 099 — Hemiplegia, Hemiparesis (if sequela coded) | High impact if sequela documented | Yes — sequela codes recapturable annually |
ICD-10 CM I61.0 itself contributes to risk adjustment scores primarily in the year the acute hemorrhage occurs, reflecting the significant resource utilization associated with hemorrhagic stroke care. Because it represents an acute event rather than a chronic condition, it does not require annual recapture in the way conditions like diabetes or COPD do. However, the long-term risk adjustment value of this diagnosis lies in the downstream sequelae — hemiplegia, cognitive impairment, dysphagia — which must be actively documented and coded at subsequent encounters to maintain an accurate risk profile for the patient. Payers reviewing risk-adjusted claims will expect to see a clear clinical trajectory from the acute event to any chronic residual conditions in the patient’s ongoing record.
🏥 MS-DRG Assignment
| DRG | Title | Relative Weight Tier |
|---|---|---|
| DRG 064 | Intracranial Hemorrhage or Cerebral Infarction with MCC | Highest weight |
| DRG 065 | Intracranial Hemorrhage or Cerebral Infarction with CC | Middle weight |
| DRG 066 | Intracranial Hemorrhage or Cerebral Infarction without CC/MCC | Lowest weight |
ICD-10 CM I61.0 groups to MDC 01 and the DRG 064-066 triad based on the presence and severity of secondary diagnoses. Most inpatient stays involving spontaneous intracerebral hemorrhage will support at least a CC, and many will support an MCC due to common complications such as acute respiratory failure, severe sepsis, or significant neurological deficits documented as encephalopathy. Sequencing I61.0 as the principal diagnosis is appropriate when the hemorrhage is the primary reason for admission and the focus of inpatient treatment. A frequent pitfall is failing to code documented complications like aspiration pneumonia or acute kidney injury, which would otherwise elevate the DRG from 066 to 065 or 064 and more accurately reflect resource consumption during the stay.
🔗 Related ICD-10-CM Codes
Other I61 Subcategory Codes: I61.1, I61.2, I61.3, I61.4, I61.9
Associated Manifestation Codes: G81.94, R47.01, R56.9, G93.41
🛠️ Commonly Associated CPT Codes
61312 — Craniotomy for evacuation of intracerebral hematoma, supratentorial; this procedure is frequently performed for large subcortical hemorrhages causing significant mass effect, and its presence on the chart strongly supports MCC-level DRG assignment. 61210 — Burr hole placement for ventricular drain or intracranial pressure monitoring device; commonly performed when intraventricular extension of the hemorrhage causes obstructive hydrocephalus. 31500 — Emergency endotracheal intubation; frequently documented in severe cases with altered mental status, supporting both severity of illness and resource utilization. 99291 — Critical care evaluation and management, first 30-74 minutes; commonly billed for the initial stabilization period of patients presenting with acute hemorrhagic stroke.
NCCI Bundling Considerations
When a craniotomy for hematoma evacuation (61312) is performed, related procedures such as burr hole placement performed as part of the same surgical approach are typically bundled and not separately reportable. Critical care codes (99291/99292) may be reported separately from procedural codes when the documentation clearly distinguishes time spent on critical care management versus time spent performing the procedure itself, with no overlap. Coders should review operative and progress notes carefully to ensure time-based critical care codes are not double-counted against procedure time.
🔬 ICD-10-PCS Crosswalk
00163ZZ — Drainage of subcortical site (basal ganglia) with no device, percutaneous approach; used when a minimally invasive aspiration of the hematoma is performed without craniotomy. 0093070 — Drainage of cerebral ventricle with drainage device, open approach; relevant when intraventricular extension requires placement of an external ventricular drain. 00N00ZZ — Release of basal ganglia, open approach; may apply in select surgical decompression procedures targeting the subcortical hematoma directly.
💊 Coding Scenarios and Examples
Scenario 1: A 68-year-old male with a history of poorly controlled hypertension presents with sudden left-sided weakness and slurred speech. CT head shows a 3 cm hemorrhage in the right basal ganglia with mild midline shift. He is managed medically in the neuro ICU with blood pressure control and develops acute respiratory failure requiring BiPAP on hospital day 2. Correct coding: I61.0, J96.00, I10, G81.94 Sequencing explanation: I61.0 is sequenced first as the principal diagnosis driving the admission, with J96.00 (acute respiratory failure) as an MCC elevating the stay to DRG 064; I10 and G81.94 are reported as secondary diagnoses reflecting underlying hypertension and the resulting hemiplegia.
Scenario 2: A 75-year-old female is admitted with a thalamic hemorrhage confirmed on MRI, with imaging report specifically noting “subcortical, thalamic distribution.” She undergoes placement of an external ventricular drain due to intraventricular extension and associated hydrocephalus. Correct coding: I61.0, I61.5, G91.4, 0093070 Sequencing explanation:I61.0 is sequenced as principal given the primary subcortical location, I61.5 is added as an additional diagnosis for the intraventricular extension component, and G91.4 captures the resulting hydrocephalus; the PCS code reflects the EVD placement procedure.
Scenario 3 (CDI Note): A 59-year-old male is admitted with imaging showing “deep hemispheric hemorrhage” without further anatomical detail specified by radiology, though the clinical note from neurology mentions “likely basal ganglia origin given hypertensive history.” Correct coding (pending query): I61.9 (as documented) — CDI query recommended to clarify anatomical location. Sequencing explanation: Without explicit confirmation of subcortical location in the final report, I61.9 would be assigned by default; a CDI query to neurology requesting confirmation of “basal ganglia” or “subcortical” terminology would support upgrading to I61.0, which does not change the DRG weight but improves overall data specificity and quality reporting.
⚠️ Coding Pitfalls and Tips
Coders frequently default to I61.9 when imaging reports use general terminology like “intracerebral hemorrhage” without specifying location, even when the clinical narrative elsewhere in the chart (neurology consult, progress notes) documents “basal ganglia” or “thalamic” involvement; a thorough chart review across all documentation sources is essential before defaulting to unspecified.
The distinction between I61.0 (subcortical) and I61.1 (cortical/lobar) can significantly affect quality metrics and registry reporting for stroke programs, even though both group to the same DRG triad, so accuracy matters beyond reimbursement alone.
When a patient has both a hemorrhagic stroke and a history of prior ischemic stroke, ensure that history codes from the Z86.73 category are added where appropriate to reflect prior cerebrovascular disease without miscoding the current event as ischemic.
Documentation of hematoma size and any mass effect or midline shift should be reviewed, as these details often correlate with the likelihood of associated complications like G93.41 (other and unspecified coma) or cerebral edema (G93.6), which can support MCC capture.
When a craniotomy (61312) is performed, verify that the operative report and pathology (if any) support the hemorrhagic, non-traumatic etiology to avoid inadvertent miscoding toward traumatic injury categories (S06.-).
Always verify that hypertension codes (I10-I16) are added as appropriate secondary diagnoses, as hypertensive intracerebral hemorrhage is the most common etiology for I61.0 and supports the overall clinical picture.
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1 ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Centers for Medicare & Medicaid Services.2 ICD-10-CM Tabular List of Diseases, FY2026, National Center for Health Statistics.
3 CMS MS-DRG Definitions Manual, Version 43, FY2026.
4 CMS-HCC Risk Adjustment Model, Version 28, 2026.
5 AHA Coding Clinic for ICD-10-CM/PCS, various issues 2024-2026.
6 AAPC CIC Study Guide, Inpatient Cerebrovascular Disease Chapter, 2025.