🧬 ICD-10 CM I62.03 — Nontraumatic Chronic Subdural Hemorrhage
Billable Code Confirmed
ICD-10 CM I62.03 is a fully specified 5-character ICD-10-CM code valid for FY2026 inpatient and outpatient facility reporting. The fifth character (3) designates the chronic temporal classification, providing the specificity required to distinguish this condition from acute and subacute subdural hemorrhage at the claim level. This code is assigned exclusively when the subdural hemorrhage is of nontraumatic origin and has been present for more than 21 days from onset.1
Non-Billable Parent Codes
I62- (Nontraumatic intracranial hemorrhage) is a category-level non-billable code requiring additional characters to specify hemorrhage type and temporal classification; it will fail claim edits if submitted as a standalone diagnosis. I62.0- (Nontraumatic subdural hemorrhage) is a 4-character subcategory code that is non-billable; it must be extended to the 5th character to capture the acute, subacute, or chronic temporal distinction before billing can occur.1,2
Clinical Context
Chronic subdural hemorrhage is distinguished from acute and subacute forms by its temporal course — defined as greater than 21 days from the initial bleed — during which the clot liquefies and the neomembranes form within the subdural space. The nontraumatic designation is a critical coding determination: I62.03 is assigned only when the physician has documented the absence of significant head trauma, or when the etiology is attributed to coagulopathy, anticoagulation therapy, spontaneous bridging vein rupture, or an underlying vascular pathology. When trauma is the documented precipitating cause, the S06.4- code family is required and an Excludes 1 violation will result from using I62.03 instead.3
Code Classification
ICD-10 CM I62.03 is a diagnosis code and must never appear in the procedure field of a claim. It classifies a pathological hemorrhagic condition within the subdural space and does not capture any surgical or therapeutic intervention. When burr hole drainage or craniotomy is performed for chronic SDH, a separate ICD-10-PCS procedure code is assigned alongside this diagnosis code, and the two code types serve entirely distinct functions within the claim.1
🔍 Code Description
Nontraumatic chronic subdural hemorrhage (I62.03) represents a collection of blood and liquefied hematoma debris in the subdural space — between the dura mater and the arachnoid membrane — that is at least 21 days old and arose in the absence of significant head trauma.3,4 Over time, the acute hematoma undergoes fibrinolysis and liquefaction, producing a characteristic hypodense collection on CT imaging, often bordered by neomembranes that form as a result of chronic inflammatory response within the subdural space. The condition disproportionately affects elderly patients, particularly those on anticoagulation therapy (warfarin, direct oral anticoagulants) or with thrombocytopenia, and is frequently triggered by trivial or entirely unrecognized minor head impacts — a key clinical distinction from the high-energy trauma that causes acute traumatic SDH. On CT imaging, chronic SDH appears hypodense (dark) relative to brain parenchyma, in contrast to the hyperdense acute phase; mixed-density collections indicate re-bleeding within an established chronic cavity, a scenario that often requires a physician query before final code assignment.4,5
The clinical presentation of chronic SDH is often insidious and can mimic dementia, stroke, or transient ischemic attack, making accurate physician documentation and timely CDI query intervention essential for correct coding and appropriate risk stratification.5 Symptoms typically include progressive headache, cognitive decline, contralateral limb weakness, gait disturbance, and in severe cases, decreased level of consciousness. In inpatient coding, I62.03 appears as both a principal diagnosis — when the patient is admitted for neurosurgical drainage or neurological management — and as a significant secondary diagnosis impacting DRG assignment and HCC risk capture. The coder must distinguish the nontraumatic etiology from traumatic subdural hemorrhage (S06.4-) and from the late effects of a prior intracranial hemorrhage coded to the I69.2- sequelae family, as these are distinct clinical states requiring different code families at different points in the patient’s care continuum.3,5
🌳 Code Tree / Hierarchy
I62 — Nontraumatic intracranial hemorrhage ❌ Non-billable
│
├── I62.0 — Nontraumatic subdural hemorrhage ❌ Non-billable
│ │
│ ├── I62.00 — Nontraumatic subdural hemorrhage, unspecified ✅ Billable
│ ├── I62.01 — Nontraumatic acute subdural hemorrhage ✅ Billable
│ ├── I62.02 — Nontraumatic subacute subdural hemorrhage ✅ Billable
│ └── I62.03 — Nontraumatic chronic subdural hemorrhage ◀ THIS CODE ✅ Billable
│
├── I62.1 — Nontraumatic extradural hemorrhage ✅ Billable
└── I62.9 — Nontraumatic intracranial hemorrhage, unspecified ✅ BillableWhy Temporal Specificity at the 5th Character Drives Code Selection
The 5th character in the I62.0x subcategory differentiates payment groupings and HCC risk scores: assigning I62.00 (unspecified) when the physician has clearly documented “chronic” is a specificity failure that may result in HCC downgrade or audit recoupment, as the chronic classification carries distinct clinical and risk-adjustment meaning that the unspecified code does not capture.2,6
Tip
When the medical record contains mixed or ambiguous documentation — such as a CT report reading “acute-on-chronic subdural hemorrhage” — query the attending physician for explicit temporal classification before assigning I62.03 versus I62.01 or I62.00. AHA Coding Clinic guidance does not permit coders to assign temporal specificity based on imaging language alone without physician attestation or co-signature.6
✅ Includes
- Chronic subdural hematoma, nontraumatic — The terms “hematoma” and “hemorrhage” are used interchangeably in ICD-10-CM for coding purposes within the I62 category; either term in physician documentation is appropriate to support I62.03 when the chronic, nontraumatic etiology is confirmed by the treating provider.1
- Chronic subdural hygroma with hemorrhagic transformation — When a hygroma (CSF collection in the subdural space) develops a hemorrhagic component over time, resulting in a chronic mixed subdural collection, I62.03 is appropriate if the physician characterizes the process as hemorrhagic or mixed in nature rather than purely hygromatous.4
- Old subdural hemorrhage, nontraumatic — Documentation describing an “old,” “organizing,” or “established” subdural hemorrhage without trauma history supports I62.03 when the physician confirms the nontraumatic etiology and chronic temporal course, even if the original onset date is not precisely known.1
❌ Excludes
Excludes 1
S06.4- — Traumatic subdural hemorrhage — This is a strict mutual exclusion; I62.03 and any code from the S06.4- family cannot be reported together on the same claim for the same encounter under any circumstances. If the hemorrhage is secondary to documented head trauma — even a minor fall with head strike — the S06.4- family applies, with a 7th character specifying encounter type (A = initial, D = subsequent, S = sequela). When a patient with a known chronic nontraumatic SDH subsequently sustains a traumatic re-bleed, the physician must be queried to determine the primary mechanism before code assignment, as the two etiologies require entirely separate code families.1,3
Danger
The most common Excludes 1 error in chronic SDH coding is assigning I62.03 when the physician has documented a fall with head strike as the precipitating event, which requires S06.4x- coding regardless of how gradual the subsequent presentation appears. Dual-coding a traumatic and nontraumatic SDH code on the same claim generates an NCCI violation and payer audit flag; clinical query is mandatory before assignment whenever the mechanism of injury is ambiguous or documentation is silent on etiology.2,3
Excludes 2
I69.2- — Sequelae of nontraumatic intracranial hemorrhage — These codes are used when the patient presents with late-effect or residual neurological deficits from a prior intracranial hemorrhage that is no longer active, not for a currently active hemorrhagic condition. I62.03 and a code from the I69.2- family may both appear on the same claim only when the patient simultaneously has a documented active chronic SDH (I62.03) and a documented residual deficit from a prior, separate hemorrhagic event; this distinction must be fully supported by physician documentation and may not be inferred by the coder from clinical context alone.1,3
📋 Clinical Overview
Temporal Classification of Nontraumatic Subdural Hemorrhage
The three temporal subtypes of nontraumatic subdural hemorrhage — acute, subacute, and chronic — are defined by the time elapsed from the initial bleeding event, with corresponding differences in CT imaging appearance, clinical presentation, and neurosurgical management strategy.4,5 These distinctions must be explicitly documented by the treating physician to support temporal code selection; radiologic terminology alone (e.g., “hypodense collection” on CT) does not authorize the coder to assign I62.03 without physician attestation. Accurate temporal coding directly impacts DRG sequencing, HCC capture, and CDI query scoring, making this one of the highest-yield coding distinctions in cerebrovascular inpatient documentation.
| Feature | I62.03 | I62.01 | I62.02 |
|---|---|---|---|
| Temporal Definition | >21 days from onset; blood liquefied, neomembranes present | <72 hours from onset; acute hyperdense collection | 4-21 days; evolving, mixed- or iso-dense collection |
| CT Appearance | Hypodense (dark); mixed density if re-bleeding has occurred | Hyperdense (bright); fresh blood clearly visible | Isodense or mixed; may require contrast to visualize |
| Typical Presentation | Gradual onset; headache, cognitive decline, gait disturbance | Acute onset; rapid neurological decline, LOC, lateralizing deficit | Subacute progression; fluctuating headache, confusion, focal deficits |
| Common Etiology | Anticoagulation, coagulopathy, elderly falls, spontaneous vessel rupture | Ruptured bridging vein, AVM, coagulopathy, high-energy mechanism | Evolution of acute bleed; similar risk factors to acute |
| DRG Implication | Groups to 065/066/067 (medical) or 025/026/027 (if surgical) | Often higher acuity; MCC-level comorbidities common at admission | Similar to chronic; surgical intervention frequently required |
Important
A primary CDI query trigger: when the attending documents “subdural hemorrhage” without a temporal qualifier, a CT imaging report showing a hypodense collection is clinically suggestive of the chronic phase — but the coder must submit a compliant physician query before assigning I62.03 over I62.00, as imaging language alone does not satisfy the documentation standard for temporal code selection.6
Manifestations & Symptom Burden
- Cognitive decline and confusion — Chronic cortical compression from the expanding subdural collection leads to progressive cognitive impairment that may be misattributed to dementia; when the physician documents the SDH as the underlying cause, do not separately code the cognitive change, as it is integral to the condition.5
- Contralateral hemiparesis or hemiplegia — Unilateral motor deficits resulting from mass effect are a common finding; if deficits persist after drainage and the SDH has resolved, assign the appropriate code from the I69.2- sequelae family at subsequent encounters per physician documentation.3
- Headache — A nearly universal but nonspecific symptom; when chronic SDH is the documented underlying cause of the headache, do not separately code the headache, as it is considered integral to the condition under ICD-10-CM guideline I.C.21.c.1.1
- Gait disturbance and fall risk — Frequently documented in elderly patients with CSDH; code fall risk with Z91.81 if explicitly documented by the treating provider, as this supports medical necessity and inpatient nursing care plan documentation.1
- Seizures — New-onset seizures may occur as a cortical irritation manifestation; assign the appropriate G40.x- code for seizure disorder if documented as a comorbidity requiring separate evaluation or treatment during the encounter.3
Tip
Manifestation coding for chronic SDH complications follows the etiology-manifestation convention: I62.03 is coded first when the manifestation (hemiparesis, cognitive impairment) is directly caused by the active hemorrhage. If the manifestation becomes the principal reason for a subsequent admission after the SDH has resolved, the I69.2- sequelae family replaces I62.03 entirely — a distinction that is commonly missed in PM&R and rehabilitation facility admissions following neurosurgical discharge when coders continue to assign I62.03 for a hemorrhage that the physician has documented as resolved.3,6
💰 HCC Risk Adjustment
| Model | HCC Category | HCC Label | RAF Weight (Community Non-Dual Aged) | Annual Capture Required |
|---|---|---|---|---|
| CMS-HCC v24 | HCC 99 | Cerebral Hemorrhage | ~1.391 | Yes |
| CMS-HCC v28 | Verify at transition | Cerebrovascular (restructured) | Verify current weight | Yes |
| ESRD Model | N/A | Not separately mapped | N/A | N/A |
ICD-10 CM I62.03 maps to HCC 99 (Cerebral Hemorrhage) under CMS-HCC Model v24, one of the more impactful cerebrovascular HCC categories given the clinical complexity and anticipated cost of chronic SDH management across anticoagulated and elderly Medicare Advantage populations.7 The RAF weight reflects the high-cost care trajectory of this diagnosis, encompassing neurosurgical intervention, ICU or step-down monitoring, anticoagulation reversal, and post-acute or inpatient rehabilitation stays. Annual recapture is mandatory — HCC credit resets at the start of each calendar year, and a patient with CSDH managed in 2025 must have the diagnosis re-documented and re-coded in 2026 to maintain the RAF impact on capitation payments. Under the phased CMS-HCC v28 transition (2024-2026 blend at 33%/67%/100%), coders should verify the updated mapping for cerebrovascular hemorrhage codes as the model has restructured several cardiovascular and cerebrovascular categories with revised weights. Payers including UHC, Aetna, and BCBS of WI conduct prospective and retrospective HCC audits and expect CT or MRI imaging documentation alongside physician attestation to support I62.03 coding during risk score validation.7
🏥 MS-DRG Assignment
| DRG | Title | Approx. Relative Weight | Approx. ALOS | Approx. GLOS |
|---|---|---|---|---|
| 065 | Intracranial Hemorrhage or Cerebral Infarction with MCC or tPA in 24 Hours | ~2.7180 | ~5.5 days | ~3.4 days |
| 066 | Intracranial Hemorrhage or Cerebral Infarction with CC or tPA in 24 Hours | ~1.4190 | ~3.6 days | ~2.4 days |
| 067 | Intracranial Hemorrhage or Cerebral Infarction without CC/MCC | ~0.9380 | ~2.6 days | ~1.6 days |
When I62.03 is the principal diagnosis in a medical admission without a qualifying OR procedure, it groups to MDC 01 and DRGs 065-067 based on the CC/MCC status of documented comorbidities at the encounter level.2,8 The relative weight difference between DRG 065 and DRG 067 is approximately 1.78 weight points — a difference that translates to substantial reimbursement variation — underscoring the CDI value of comprehensive comorbidity documentation, including acute respiratory failure (J96.00), severe sepsis (A41.9 + R65.20), and malnutrition (E43). When a qualifying OR procedure such as burr hole drainage (ICD-10-PCS 00C43ZZ) or open craniotomy (ICD-10-PCS 00C40ZZ) is performed during the same admission, the case re-groups to DRG 025/026/027 (Craniotomy and Endovascular Intracranial Procedures), which carry significantly higher relative weights than the medical DRGs. Chronic SDH itself does not carry MCC or CC designation in the MS-DRG system but consistently co-presents with conditions that do — anticoagulation drug use (Z79.01), atrial fibrillation (I48.19), and chronic kidney disease — making complete comorbidity capture essential for accurate DRG assignment and appropriate reimbursement.6,8
🔗 Related ICD-10-CM Codes
Nontraumatic Intracranial Hemorrhage Family
- I62.00 — Nontraumatic subdural hemorrhage, unspecified; assign only when the physician has not documented the temporal phase and a query is not possible or appropriate
- I62.01 — Nontraumatic acute subdural hemorrhage; onset within 72 hours, hyperdense collection on CT
- I62.02 — Nontraumatic subacute subdural hemorrhage; 4-21 days from onset, evolving isodense or mixed collection
- I62.1 — Nontraumatic extradural (epidural) hemorrhage; collection above the dura, distinct anatomically and clinically from subdural hemorrhage
- I62.9 — Nontraumatic intracranial hemorrhage, unspecified; assign only when type cannot be specified after appropriate query
- I61.9 — Nontraumatic intracerebral hemorrhage, unspecified; within the brain parenchyma itself, not within the subdural space
Sequelae, Comorbidities, and Associated Conditions
- I69.2- — Sequelae of nontraumatic intracranial hemorrhage; for late effects and residual neurological deficits after the active hemorrhage has resolved (verify specific character requirements before assignment)
- I48.19 — Other persistent atrial fibrillation; frequent comorbidity in anticoagulated patients presenting with CSDH
- Z79.01 — Long-term (current) use of anticoagulants; should be coded when anticoagulation is documented as a contributing risk factor
- Z91.81 — History of falling; documents fall risk in elderly CSDH patients and supports nursing care plan complexity
- E43 — Unspecified severe protein-calorie malnutrition; MCC-level comorbidity commonly present in elderly or debilitated CSDH patients
🛠️ Commonly Associated CPT Codes
- 61312 — Craniectomy or craniotomy for evacuation of hematoma, supratentorial; extradural or subdural. Primary open surgical procedure for chronic SDH when burr hole drainage is insufficient or the collection is organized and cannot be adequately aspirated; document laterality in the operative note, as modifier -RT or -LT may be required by payers including UHC and Aetna, and bilateral craniotomies require modifier -50 or individual line-item reporting per payer policy.9
- 61105 — Twist drill hole(s) for intracranial aspiration or decompression. Most commonly performed procedure for chronic SDH given the liquefied nature of the chronic collection; used for bedside or OR drainage of the subdural cavity via small-diameter burr holes and is frequently selected over open craniotomy in elderly or high-surgical-risk patients. Verify NCCI bundling with any separately reported neurosurgical codes on the same date of service, as this code cannot be reported with 61312 for the same operative site.9
- 70450 — CT scan of head/brain without contrast. Primary imaging modality for initial diagnosis and post-drainage surveillance of chronic SDH; documents the characteristic hypodense subdural collection and midline shift that establish medical necessity for inpatient admission or surgical intervention. When CT imaging is performed on the same date as a surgical procedure by the same provider, verify whether it is bundled into the global surgical package before separate billing.9
- 70553 — MRI brain with and without contrast. Utilized when CT findings are equivocal, when the collection is isodense to brain parenchyma (as in subacute-to-chronic transition), or when underlying pathology such as dural metastasis or chronic infectious meningitis must be excluded. More sensitive than CT for bilateral isodense collections and for identifying neomembrane formation; subject to prior authorization requirements in the outpatient setting under most commercial payer contracts.9
NCCI Bundling Considerations
When imaging (e.g., 70450) and a surgical procedure (e.g., 61312) are billed on the same date, imaging may be bundled into the global surgical package if performed by the same provider in the same session; facility coders should follow hospital charge capture protocols and confirm independent medical necessity before separate reporting. Burr hole codes (61105) and craniotomy codes (61312) are never reported together for the same operative site, as the burr hole is integral to and included in the craniotomy approach. In the inpatient profee coding context, NCCI edits apply at the claim level and should be reviewed for any combination of neurosurgical codes assigned within the same encounter.9
🔬 ICD-10-PCS Crosswalk
- 00C40ZZ — Extirpation of Subdural Space, Open Approach. Assigned when the chronic SDH is evacuated via open craniotomy; the root operation “Extirpation” captures removal of solid or semisolid matter from a body part and is appropriate when the organized, membranous hematoma cannot be drained percutaneously. This is the most appropriate PCS code when intraoperative findings document an organized or membranous collection requiring open excision.10
- 00C43ZZ — Extirpation of Subdural Space, Percutaneous Approach. Assigned when the chronic SDH is drained via burr hole or twist drill under a percutaneous approach; the approach character (3 = Percutaneous) distinguishes this from the open craniotomy code and is the preferred PCS code for most routine chronic SDH drainage procedures given the liquefied state of the collection at this stage.10
- 009400Z — Drainage of Subdural Space with Drainage Device, Open Approach. Used when a closed-system drain or subdural catheter is placed intraoperatively and left in position postoperatively; the device character (0 = Drainage Device) differentiates this from extirpation codes when ongoing drainage rather than one-time evacuation is the primary operative intent.10
- 009430Z — Drainage of Subdural Space with Drainage Device, Percutaneous Approach. Selected when a drain or catheter is placed within the subdural space via burr hole technique and left for continued drainage; this code is commonly used for recurrent CSDH or when residual fluid requires closed-system postoperative decompression following the initial procedure.10
💊 Coding Scenarios and Examples
Scenario 1: Elderly Anticoagulated Patient Admitted for Chronic SDH An 82-year-old male on warfarin for persistent atrial fibrillation presents with a 4-week history of progressive confusion, left-sided arm weakness, and headache. CT head confirms a right-sided hypodense subdural collection with 7mm midline shift. Neurosurgery performs right-sided burr hole drainage; warfarin is held and INR is corrected with vitamin K and FFP. Comorbidities include hypertension and chronic kidney disease stage 3 unspecified.
Correct Codes: I62.03, I48.19, Z79.01, I10, N18.30 Sequencing: I62.03 as principal diagnosis (reason for admission and surgical intervention); I48.19 as significant CC comorbidity driving anticoagulation and fall risk; Z79.01 documents active anticoagulation as a contributing factor to hemorrhage risk; I10 and N18.30 as additional chronic comorbidities. CDI Note: Query the physician to explicitly confirm “chronic” temporal classification and “nontraumatic” etiology if not directly stated in the admission note or operative documentation. If warfarin is documented as a contributing cause of the hemorrhage, the coding of Z79.01 is mandatory, not optional, and supports both medical necessity and HCC capture.3,6
Scenario 2: Chronic SDH as Significant Secondary Diagnosis in PM&R Admission A 71-year-old female admitted to inpatient rehabilitation following left hip fracture surgical repair is found on routine neurological screen to have bilateral chronic subdural hematomas on CT, diagnosed 6 weeks prior and currently managed conservatively. No new neurological symptoms; neurology confirms hematomas are stable. Principal reason for admission is post-surgical hip fracture rehabilitation.
Correct Codes: Z47.1 (principal), I62.03 (significant secondary comorbidity) Sequencing: Z47.1 as principal diagnosis capturing the orthopedic aftercare reason for admission; I62.03 as a significant active secondary diagnosis affecting nursing monitoring, activity restrictions, and care plan complexity. CDI Note: Bilateral chronic SDH is coded once with I62.03 — ICD-10-CM does not provide a bilateral laterality character for this code, and duplicate reporting of I62.03 is incorrect. Confirm with the physician that the SDH is still active and clinically managed, not resolved; if resolved, the I69.2- sequelae family applies, and I62.03 should not be assigned.1,3
Scenario 3: Acute-on-Chronic SDH with Re-Bleeding — Query Required A 68-year-old male with a chronic SDH diagnosed 5 weeks ago presents with sudden-onset worsening headache and new right-sided weakness. CT imaging shows a mixed-density subdural collection with a hyperdense component within the previously hypodense chronic cavity, consistent with acute hemorrhage into a chronic SDH. Patient undergoes emergent craniotomy for evacuation.
Correct Codes: Query required before final assignment — I62.03 and/or I62.01 pending physician response. Sequencing: This scenario mandates a physician query. The CT report documenting a mixed-density collection does not authorize dual coding of I62.03 and I62.01 without explicit physician documentation that both an acute and chronic hemorrhage are independently present and clinically managed. The attending must be queried to specify whether the primary condition is best classified as re-bleeding into a chronic cavity (chronic dominant) or a new acute hemorrhagic event superimposed on a chronic collection (acute dominant). CDI Note: Acute-on-chronic SDH represents one of the highest-value CDI query opportunities in cerebrovascular inpatient coding because imaging and physician language are frequently discordant, and the correct temporal code assignment has direct DRG and HCC implications. AHA Coding Clinic supports physician query as the appropriate mechanism for resolving this type of documentation ambiguity before code assignment.6
⚠️ Coding Pitfalls and Tips
- Do not assign I62.00 when the physician has documented “chronic.” Using the unspecified temporal code when “chronic” is clearly documented is a specificity failure and a common finding in external coding audits; I62.03 must be assigned whenever the physician has explicitly stated or confirmed the chronic temporal phase.1
- Never assign I62.03 when trauma is the documented precipitating cause. Even a minor fall with head strike documented as the inciting event requires the S06.4- code family; the Excludes 1 notation at the I62 category level is absolute and will generate a claim edit if I62.03 is used for a traumatic mechanism.1,3
- Do not separately code headache or cognitive decline when integral to the SDH. Symptoms routinely associated with I62.03 that are not separately evaluated or independently treated during the encounter are not coded per ICD-10-CM guideline I.C.21.c.1 (signs and symptoms guideline for confirmed diagnoses).1
- Always code Z79.01 when anticoagulation is documented as a contributing factor. This code is frequently omitted despite being a mandatory secondary code when the physician documents anticoagulant use as clinically relevant to the hemorrhage; it supports medical necessity, HCC capture, and MA plan audit defense.3
- Shift from I62.03 to the I69.2- sequelae family when the SDH has resolved. If the patient is readmitted for residual neurological deficits from a prior SDH that is documented as resolved, I62.03 is incorrect; the I69.2- family captures the ongoing impact of the resolved hemorrhage and is required at that stage of care.1,3
- Bilateral chronic SDH is coded once — do not duplicate I62.03. There is no laterality character in this code; bilateral involvement is a clinical finding but does not result in dual reporting of the diagnosis code. Bilateral surgical procedures are captured in the ICD-10-PCS procedure code assignments, not through duplication of the diagnosis code.1