2027 ICD-10-CM Diagnosis Code S06.5X4ATraumatic subdural hemorrhage with loss of consciousness of 6 hours to 24 hours, initial encounter
ICD-10-CM Codes›S00–T88›S00-S09›S06
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 397
- 7th Character A — Initial Encounter
- Not Chronic
S06.5X4A is a billable ICD-10-CM diagnosis code for traumatic subdural hemorrhage with loss of consciousness of 6 hours to 24 hours, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 82 through 84, 963 through 965. 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 383 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Traumatic brain injury (TBI); concussion, initial encounter.
For Medicare Advantage risk adjustment, S06.5X4A maps to CMS-HCC Category 397 (Major Head Injury with Loss of Consciousness > 1 Hour) under the V28 model, adding a risk factor of about 0.199 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
S06.5X4A 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.
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Intracranial injury (S06). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027, published by CMS and the National Center for Health Statistics.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to S06.5X4A: its own notes plus those printed at S06.5, S06, block S00-S09, and Chapter 19. 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.
- traumatic brain injury
- injuries of ear
- injuries of eye
- injuries of face [any part]
- injuries of gum
- injuries of jaw
- injuries of oral cavity
- injuries of palate
- injuries of periocular area
- injuries of scalp
- injuries of temporomandibular joint area
- injuries of tongue
- injuries of tooth
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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.
- burns and corrosions (T20-T32)
- effects of foreign body in ear (T16)
- effects of foreign body in larynx (T17.3)
- effects of foreign body in mouth NOS (T18.0)
- effects of foreign body in nose (T17.0-T17.1)
- effects of foreign body in pharynx (T17.2)
- effects of foreign body on external eye (T15.-)
- frostbite (T33-T34)
- insect bite or sting, venomous (T63.4)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code, if applicable, for traumatic brain compression or herniation (S06.A-)
- code, if applicable, to identify mild neurocognitive disorders due to known physiological condition (F06.7-)
- code to identify any retained foreign body, if applicable (Z18.-)
Code Also
A second code may be needed to fully describe the condition; the note gives no sequencing direction.
- for any associated infection
Notes
General instructions on how these codes are used.
- 7th characters D and S do not apply to codes in category S06 with 6th character 7 - death due to brain injury prior to regaining consciousness, or 8 - death due to other cause prior to regaining consciousness.
- Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
- The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.
7th Character
Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.
- The appropriate 7th character is to be added to each code from category S06, except as noted below
- Ainitial encounter this code
- Dsubsequent encounter
- Ssequela
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name S06.5X4A, its category, or a range that includes it.
Excludes1 7
These codes carry an Excludes1 note naming S06.5X4A: they are not reported together with it, unless the two conditions are unrelated.
- G31.84 Mild cognitive impairment of uncertain or unknown etiologycognitive impairment due to intracranial or head injury (S06.-) names S06.-, which includes this code
- Block I60-I69 Cerebrovascular diseasestraumatic intracranial hemorrhage (S06.-) names S06.-, which includes this code
- I69 Sequelae of cerebrovascular diseasesequelae of traumatic intracranial injury (S06.-) names S06.-, which includes this code
- I69.8 Sequelae of other cerebrovascular diseasessequelae of traumatic intracranial injury (S06.-) names S06.-, which includes this code
- I69.9 Sequelae of unspecified cerebrovascular diseasessequelae of traumatic intracranial injury (S06.-) names S06.-, which includes this code
- P52 Intracranial nontraumatic hemorrhage of newbornintracranial hemorrhage due to other injury (S06.-) names S06.-, which includes this code
- S09.0 Injury of blood vessels of head, not elsewhere classifiedinjury of cerebral blood vessels (S06.-) names S06.-, which includes this code
Excludes2 1
These codes carry an Excludes2 note naming S06.5X4A: its condition is not part of those codes, and both may be reported when the patient has both.
- S06.3 Focal traumatic brain injury
Code First 6
These codes say to code first a condition named in the note, and S06.5X4A is one of the conditions named.
- F02 Dementia in other diseases classified elsewheretraumatic brain injury (S06.-) names S06.-, which includes this code
- F06.7 Mild neurocognitive disorder due to known physiological conditiontraumatic brain injury (S06.-) names S06.-, which includes this code
- F48.2 Pseudobulbar affectsequelae of traumatic intracranial injury (S06.-) names S06.-, which includes this code
- R40.2 Comaintracranial injury (S06.-) names S06.-, which includes this code
- S04 Injury of cranial nerveany associated intracranial injury (S06.-) names S06.-, which includes this code
- S06.A Traumatic brain compression and herniationtraumatic subdural hemorrhage (S06.5-) names S06.5-, which includes this code
Use Additional Code 1
These codes say to use an additional code from the note, and S06.5X4A is one of the codes named.
Code Also 2
These codes say S06.5X4A may also be needed to fully describe the condition. The note gives no sequencing direction.
Notes 1
These notes mention S06.5X4A.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Traumatic Brain Injury
Traumatic brain injury (TBI) is a sudden injury that causes damage to the brain. It may happen when there is a blow, bump, or jolt to the head. This is a closed head injury. A TBI can also happen when an object penetrates the skull. This is a penetrating injury.
The full article covers:
- What is traumatic brain injury (TBI)?
- What causes traumatic brain injury (TBI)?
- Who is at risk for traumatic brain injury (TBI)?
- What are the symptoms of traumatic brain injury (TBI)?
- How is traumatic brain injury (TBI) diagnosed?
- What are the treatments for traumatic brain injury (TBI)?
- Can traumatic brain injury (TBI) be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S06.5X4A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S06.5X4AOverview
Is S06.5X4A a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report traumatic subdural hemorrhage with loss of consciousness of 6 hours to 24 hours, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What does the 7th character A in S06.5X4A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for traumatic subdural hemorrhage with loss of consciousness of 6 hours to 24 hours, such as an emergency visit or first evaluation.
What MS-DRG does S06.5X4A group to?
When traumatic subdural hemorrhage with loss of consciousness of 6 hours to 24 hours, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 964, 83, 84, 965, 82, 963, with relative weights from 0.9601 to 2.6361 depending on complications. Higher weights mean higher Medicare reimbursement.
Is S06.5X4A a CC or MCC?
CMS lists S06.5X4A 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 383 closely related codes in its exclusion list.
Can S06.5X4A be reported with S09.90?
Not as a rule. The Excludes1 note at S06, which applies to S06.5X4A, lists "head injury NOS (S09.90)". 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 S06.5X4A?
S06.5X4A (traumatic subdural hemorrhage with loss of consciousness of 6 hours to 24 hours, initial encounter) maps to CMS-HCC Category 397 (Major Head Injury with Loss of Consciousness > 1 Hour), commonly written as HCC 397, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 166 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 S06.5X4A risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, S06.5X4A adds a risk adjustment factor of about 0.199 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.052 to 0.349 depending on the payment segment). HCC 397 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 397 category page.
