🧬 ICD-10 CM S06.4X9D — Epidural Hemorrhage With Loss Of Consciousness Of Unspecified Duration, Subsequent Encounter
Billable Code Confirmed
ICD-10 CM S06.4X9D is a complete, 7-character code — S06.4 (epidural hemorrhage) + X (placeholder) + 9 (LOC of unspecified duration) + D (subsequent encounter) — making it valid for claim submission with no further specificity required.¹
Non-Billable Parent Codes
S06.4X9 (Epidural hemorrhage with loss of consciousness of unspecified duration) is a header code missing the 7th-character encounter type. S06.4X (Epidural hemorrhage) and S06.4 (Epidural hemorrhage) are broader header categories that cannot be billed on their own.¹
Clinical Context
The “9” duration character signals that the treating provider documented loss of consciousness but did not specify its length; the “D” 7th character means this encounter is for routine healing/follow-up rather than active initial management of the bleed.²
Code Classification
This is a diagnosis code (ICD-10-CM), not a procedure code — it does not itself trigger DRG surgical weighting and should be paired with any performed procedure codes separately.
🔍 Code Description
Epidural (extradural) hemorrhage is bleeding between the dura mater and the inner skull table, most often arterial in origin and classically associated with a lucid interval followed by rapid neurologic decline. S06.4X9D specifically captures the subsequent-encounter phase of care for a patient whose loss of consciousness duration at the time of injury was never pinned down in the documentation — a common scenario when a patient is transferred in from an outside facility without a clear timeline, or when EMS/ED documentation is incomplete on arrival.
The 7th-character “D” distinguishes this from the initial encounter, which most inpatient coders will see on the index admission. A subsequent encounter applies to visits after the patient has received active treatment and is now receiving routine care during the healing or recovery phase — think a rehab-facility admission, a post-discharge follow-up CT, or a readmission for an unrelated condition where the epidural bleed history is still being actively managed or monitored, distinct from S06.4X9A (initial encounter) or S06.4X9S (sequela, used once a residual late effect like post-traumatic seizure disorder is the focus of care).
🌳 Code Tree / Hierarchy
S06.4 [Epidural hemorrhage] ❌ Non-billable
│
├── S06.4X0 [Without loss of consciousness] ❌ Non-billable
│ ├── S06.4X0A [initial encounter] ✅ Billable
│ ├── S06.4X0D [subsequent encounter] ✅ Billable
│ └── S06.4X0S [sequela] ✅ Billable
│
├── S06.4X1 [LOC 30 min or less] ❌ Non-billable
│
├── S06.4X9 [LOC of unspecified duration] ❌ Non-billable
│ │
│ ├── S06.4X9A [initial encounter] ✅ Billable
│ ├── S06.4X9D [subsequent encounter] ◀ THIS CODE ✅ Billable
│ └── S06.4X9S [sequela] ✅ Billable
│
└── S06.4XA [LOC status unknown] ❌ Non-billableSpecificity Insight
Payers will deny a claim submitted with the header S06.4X9 — the 7th character is mandatory. If the LOC duration is later specified in the record (e.g., “LOC of 45 minutes”), re-code to the matching duration subcategory such as S06.4X1D rather than defaulting to “unspecified.”
Tip
Query the provider whenever “LOC unspecified duration” appears on a subsequent visit note if the initial ED/trauma record actually documented a duration — capturing the specific duration code supports more precise severity documentation for audit defense.
✅ Includes
Traumatic brain injury — S06.4X9D falls under the general “traumatic brain injury” inclusion note that applies across the entire S06 category, covering closed and open intracranial hemorrhagic injuries of traumatic origin.³
❌ Excludes
Excludes 1
S09.90 (Head injury NOS) cannot be reported with S06.4X9D — if the intracranial injury is specified as epidural hemorrhage, the vague “head injury NOS” code is inappropriate and would misrepresent specificity already available in the chart.¹ P10-P15 (Birth trauma) and O70-O71 (Obstetric trauma) are excluded because those code sets exclusively capture perinatal/obstetric mechanisms, not traumatic injury in a general trauma patient.
Danger
The most common Excludes1 error is defaulting to a nonspecific head-injury code out of documentation uncertainty rather than querying the provider — this both violates the Excludes1 note and understates injury severity for DRG/HCC purposes.
Excludes 2
T20-T32 (Burns and corrosions) and T16 (Effects of foreign body in ear) may be coded in addition to S06.4X9D when a patient has both conditions from the same traumatic event — for example, a blast injury patient with both an epidural hemorrhage and separate burn injuries.
📋 Clinical Overview
Duration-Specificity vs. Encounter-Type Selection
Coders frequently conflate the two axes that build a complete S06.4X code: the 6th-character digit specifies LOC duration, while the 7th character specifies encounter type (initial, subsequent, sequela). Both axes must be documented and both drive code selection independently.
| Feature | S06.4X9D | Related S06.4X9A | Related S06.4X0D |
|---|---|---|---|
| LOC duration | Unspecified | Unspecified | No LOC documented |
| Encounter phase | Subsequent (healing/follow-up) | Initial (active treatment) | Subsequent (healing/follow-up) |
| Typical care setting | Rehab, SNF, follow-up outpatient/inpatient visit | ED, trauma bay, initial hospitalization | Rehab, SNF, follow-up visit |
Important
If a subsequent-encounter TBI code like S06.4X9D is being used as principal diagnosis on an acute inpatient claim, that is a CDI trigger — confirm whether the admission is truly for ongoing management of the healing epidural hemorrhage or whether a new acute event (recurrent bleed) actually warrants an initial-encounter code instead.
Manifestations & Symptom Burden
During the subsequent-encounter phase, documentation commonly reflects residual headache, cognitive fog, or post-concussive symptoms rather than acute neurologic decline. Persistent altered mental status at this stage should prompt a query, since it may indicate a new bleed (requiring an initial-encounter code) rather than expected healing.
Tip
Don’t assume “subsequent encounter” automatically means resolved — the patient can still be quite symptomatic; the 7th character reflects the phase of treatment, not symptom severity.
💰 HCC Risk Adjustment
Under the CMS-HCC V28 model fully phased in for payment year 2026, the major head-injury payment categories (HCC 397 and HCC 398) are populated by initial-encounter (“A” 7th-character) codes documenting acute loss-of-consciousness duration.⁴ Subsequent-encounter codes in this same clinical family are generally excluded from those payment HCCs because the model is designed to capture the acute health-event severity, not the follow-up phase. Flag for independent verification against the current CMS-HCC V28 ICD-10-CM mapping file before relying on this for RAF calculations, since crosswalk files are refreshed with each model update.
🏥 MS-DRG Assignment
| DRG | Title | CC/MCC Status |
|---|---|---|
| 083 | Traumatic Stupor & Coma, Coma <1 Hr | w MCC |
| 084 | Traumatic Stupor & Coma, Coma <1 Hr | w CC |
| 085 | Traumatic Stupor & Coma, Coma <1 Hr | w/o CC/MCC |
These DRGs are typically driven by an initial-encounter intracranial hemorrhage code as principal diagnosis; S06.4X9D as a subsequent-encounter code will rarely group here as principal diagnosis and more often appears as a secondary diagnosis, shifting weight only if it supports a CC/MCC designation on an unrelated admission. There is no diagnosis-specific NCD for S06.4X9D itself; coverage considerations attach instead to the procedures performed to manage or monitor the hemorrhage (craniotomy/hematoma evacuation, follow-up CT/MRI imaging), which are subject to your MAC’s (Noridian JE/JF) local coverage determinations on medical necessity for repeat neuroimaging and neurosurgical intervention.⁵ Flag for live verification against the Medicare Coverage Database for the specific LCD applicable to the procedure billed alongside this diagnosis.
🔗 Related ICD-10-CM Codes
Same subcategory family (S06.4X — Epidural hemorrhage): S06.4X0A, S06.4X0D, S06.4X0S (without LOC), S06.4X9A (initial encounter), S06.4X9S (sequela)
Other traumatic intracranial hemorrhage, subsequent encounter: S06.5X0D (Traumatic subdural hemorrhage without LOC), S06.6X0D (Traumatic subarachnoid hemorrhage without LOC), S06.1X0D (Traumatic cerebral edema)
🛠️ Commonly Associated CPT Codes
- 61312 — Craniectomy/craniotomy for evacuation of hematoma, supratentorial; extradural or subdural. Billed when a subsequent admission requires surgical re-evacuation of a re-accumulated epidural collection.⁶
- 61314 — Same procedure, infratentorial approach; used for posterior fossa epidural collections.
- 70450 — CT head/brain without contrast. The standard follow-up imaging study to confirm resolution or re-accumulation during the healing phase.
- 70460 — CT head/brain with contrast, used selectively when infection or vascular complication is suspected.
- 99231, 99232, 99233 — Subsequent hospital inpatient/observation care, reflecting the ongoing daily management documented during a subsequent-encounter admission.
🏷️ Modifier Reference
| Modifier | Name | When to Apply |
|---|---|---|
| -25 | Significant, Separately Identifiable E/M | Apply when a significant, separately identifiable E/M service is performed the same day as a minor procedure related to monitoring the healing hemorrhage. |
| -59 | Distinct Procedural Service | Apply when imaging or a minor procedure performed during the subsequent-encounter visit is distinct from another same-day bundled service. |
| -78 | Unplanned Return to OR | Apply if the patient requires an unplanned return to the operating room for re-evacuation of the epidural collection during the same postoperative period. |
| -79 | Unrelated Procedure by Same Physician During Postop Period | Apply when a procedure unrelated to the epidural hemorrhage is performed by the same surgeon during a global period tied to a prior craniotomy. |
NCCI Bundling Considerations
CT head/brain codes (70450, 70460, 70470) will bundle under NCCI edits when multiple contrast phases of the same study are billed on the same date; only the single most comprehensive code (e.g., 70470 for combined without/with contrast) should be reported rather than stacking the individual component codes.
🔬 ICD-10-PCS Crosswalk
00980ZZ— Reposition, dura mater, open approach — used if a subsequent-encounter admission involves surgical exploration of the epidural space without new hematoma evacuation.00983ZZ— Reposition, dura mater, percutaneous approach — for a minimally invasive re-exploration procedure.00N03ZZ— Release, epidural space, open approach — applicable when a surgical decompression/evacuation of a re-accumulated epidural collection is performed during the subsequent encounter. Flag for independent verification — exact PCS root operation depends on the specific procedure note documentation.
💊 Coding Scenarios and Examples
Example 1
Clinical Scenario: A patient with a known epidural hemorrhage sustained three weeks prior (LOC duration never documented at the outside facility) is admitted to inpatient rehab for continued cognitive rehabilitation and monitoring. No new acute bleed is identified.
| Field | Code | Rationale |
|---|---|---|
| PDx | S06.4X9D | Subsequent encounter for ongoing management of the healing epidural hemorrhage with undocumented LOC duration. |
| CPT | 99232 | Moderate-complexity subsequent hospital care reflecting daily rehab-unit management. |
Tip
Confirm the admission is genuinely for continued management rather than a new acute event before finalizing this as principal diagnosis.
Example 2
Clinical Scenario: A patient readmitted for a re-accumulated epidural collection three weeks after initial injury undergoes repeat craniotomy for evacuation.
| Field | Code | Rationale |
|---|---|---|
| CPT | 61313 | Craniotomy for evacuation of the re-accumulated supratentorial epidural hematoma. |
| PDx | S06.4X9D | Subsequent-encounter code appropriate since this is ongoing management of the original injury, not a brand-new traumatic event. |
Tip
If imaging clearly identifies this as a new traumatic bleed unrelated to the original injury, an initial-encounter code would apply instead — confirm mechanism and timeline with the surgeon.
Example 3
Clinical Scenario: A follow-up outpatient-to-inpatient conversion visit for a persistent headache three weeks post-epidural hemorrhage; CT head is repeated and shows resolving hematoma with no intervention needed.
| Field | Code | Rationale |
|---|---|---|
| PDx | S06.4X9D | Subsequent encounter for routine follow-up during the healing phase. |
| CPT | 70450 | Follow-up CT head without contrast to assess hematoma resolution. |
Tip
Sequela coding (S06.4X9S) would only apply once care shifts to treating a late effect (e.g., post-traumatic headache syndrome) rather than the hemorrhage itself.
⚠️ Coding Pitfalls and Tips
- Pitfall 1: Reporting the non-billable header S06.4X9 without the 7th character; Tips: always confirm all three positions of the extension (duration digit + encounter letter) are present before finalizing the code.
- Pitfall 2: Confusing “subsequent encounter” with “resolved condition”; Tips: subsequent encounter reflects treatment phase, not symptom resolution — patients can still be actively symptomatic.
- Pitfall 3: Defaulting to S06.4X9D (unspecified duration) when the original trauma note actually documented a specific LOC timeframe; Tips: review the full chart history, not just the current encounter note, before finalizing duration specificity.
- Pitfall 4: Using a subsequent-encounter code as principal diagnosis on an acute inpatient stay without confirming medical necessity for that admission; Tips: query for a new acute finding if severity of presentation suggests a fresh bleed rather than routine follow-up.
- Pitfall 5: Assuming this code maps to an HCC category; Tips: verify current-year V28 crosswalk file directly, since subsequent-encounter TBI codes are generally excluded from the major head-injury payment HCCs.
📚 Sources
1. Centers for Medicare & Medicaid Services and National Center for Health Statistics. *ICD-10-CM FY2026 Full Code List.* CMS; 2026. https://www.cms.gov/icd10m/ 2. ICD-10-CM Official Guidelines for Coding and Reporting, FY2026. CMS/NCHS; 2026. 3. AutoICD API. *S06.4X — Epidural hemorrhage, coding notes.* 2026. https://autoicdapi.com/icd10/S06.4X 4. HCC Buddy. *CMS-HCC V28 Category 397/398 — Major Head Injury.* 2026. https://hccbuddy.com/hcc/v28/397 5. Noridian Healthcare Solutions. *Medicare Coverage Database — Local Coverage Determinations, JE/JF.* CMS; 2026. 6. CMS Physician Fee Schedule. *PPRRVU2026_Jan_QPP File.* CMS; January 2026.Sources listed above correspond to superscript citations throughout this note. Verify all Medicare payment figures against your current CMS PFS Lookup tool and applicable MAC LCD prior to claim submission. Please use the latest AAPC/AHIMA Coding Books to verify each code within this note.