2027 ICD-10-CM Diagnosis Code S06.A1XSTraumatic brain compression with herniation, sequela

ICD-10-CM Codes›S00–T88›S00-S09›S06

ICD-10-CM S06.A1XS
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S06.A1XS is a billable ICD-10-CM diagnosis code for traumatic brain compression with herniation, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 913 through 914. The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. Coders also document this condition as herniation of brain due to traumatic compression of brain. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.

S06.A1XS no longer risk-adjusts for Medicare Advantage: it mapped to HCC 167 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 167, ESRD (V21) category 167, and ESRD (V24) category 167 for payment year 2027.

Code Identity

ICD-10-CM Code
S06.A1XS
Billable Status
Yes — Valid for Submission
Code Describes
Traumatic brain compression with herniation, sequela
Short Description
Traumatic brain compression with herniation, sequela
Same as the full description in the CMS dataset.
Parent Code
S06.A1
Traumatic brain compression with herniation

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS00-S09Injuries to the head
CategoryS06Intracranial injury
This CodeS06.A1XSTraumatic brain compression with herniation, sequela

Code EditsBilling

Medicare Code Editor checks that affect claim validity for S06.A1XS.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Present on Admission (POA)Billing

S06.A1XS is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Injuries to the head (S00-S09).

Medicare Risk Adjustment (HCC)Billing

S06.A1XS no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 167
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
Other CMS Models
PACE (CMS-HCC V22): HCC 167 · ESRD (V21): HCC 167 · ESRD (V24): HCC 167
ESRD V21 weights: 0.017 dialysis, 0.000–0.184 functioning graft · ESRD V24 weights: 0.043 dialysis, 0.000–0.239 functioning graft
Part D (RxHCC)
Not mapped
S06.A1XS does not risk-adjust in the RxHCC prescription drug model

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.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Herniation of brain due to traumatic compression of brain

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.A1XS: its own notes plus those printed at S06.A, 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.

From S06 Intracranial injury applies to 569 codes
  • traumatic brain injury
From Block S00-S09 Injuries to the head applies to 1,934 codes
  • 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.

From S06 Intracranial injury applies to 569 codes

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.

From Block S00-S09 Injuries to the head applies to 1,934 codes
  • 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)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Code First

The underlying condition named in the note is sequenced before this code.

From S06.A Traumatic brain compression and herniation applies to 6 codes
  • the underlying traumatic brain injury, such as:
  • diffuse traumatic brain injury (S06.2-)
  • focal traumatic brain injury (S06.3-)
  • traumatic subdural hemorrhage (S06.5-)
  • traumatic subarachnoid hemorrhage (S06.6-)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From S06 Intracranial injury applies to 569 codes
  • code, if applicable, to identify mild neurocognitive disorders due to known physiological condition (F06.7-)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • 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.

From S06 Intracranial injury applies to 569 codes
  • any associated:
  • open wound of head (S01.-)
  • skull fracture (S02.-)
From Block S00-S09 Injuries to the head applies to 1,934 codes
  • for any associated infection

Notes

General instructions on how these codes are used.

From S06 Intracranial injury applies to 569 codes
  • 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.
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • 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.

From S06 Intracranial injury applies to 569 codes
  • The appropriate 7th character is to be added to each code from category S06, except as noted below
Values for category S06 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela this code

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.A1XS, its category, or a range that includes it.

Excludes1 8

These codes carry an Excludes1 note naming S06.A1XS: they are not reported together with it, unless the two conditions are unrelated.

  • G31.84 Mild cognitive impairment of uncertain or unknown etiology
    cognitive impairment due to intracranial or head injury (S06.-) names S06.-, which includes this code
  • G93.5 Compression of brain
    traumatic compression of brain (S06.A-) names S06.A-, which includes this code
  • Block I60-I69 Cerebrovascular diseases
    traumatic intracranial hemorrhage (S06.-) names S06.-, which includes this code
  • I69 Sequelae of cerebrovascular disease
    sequelae of traumatic intracranial injury (S06.-) names S06.-, which includes this code
  • I69.8 Sequelae of other cerebrovascular diseases
    sequelae of traumatic intracranial injury (S06.-) names S06.-, which includes this code
  • I69.9 Sequelae of unspecified cerebrovascular diseases
    sequelae of traumatic intracranial injury (S06.-) names S06.-, which includes this code
  • P52 Intracranial nontraumatic hemorrhage of newborn
    intracranial hemorrhage due to other injury (S06.-) names S06.-, which includes this code
  • S09.0 Injury of blood vessels of head, not elsewhere classified
    injury of cerebral blood vessels (S06.-) names S06.-, which includes this code

Code First 5

These codes say to code first a condition named in the note, and S06.A1XS is one of the conditions named.

  • F02 Dementia in other diseases classified elsewhere
    traumatic brain injury (S06.-) names S06.-, which includes this code
  • F06.7 Mild neurocognitive disorder due to known physiological condition
    traumatic brain injury (S06.-) names S06.-, which includes this code
  • F48.2 Pseudobulbar affect
    sequelae of traumatic intracranial injury (S06.-) names S06.-, which includes this code
  • R40.2 Coma
    intracranial injury (S06.-) names S06.-, which includes this code
  • S04 Injury of cranial nerve
    any associated intracranial injury (S06.-) names S06.-, which includes this code

Use Additional Code 5

These codes say to use an additional code from the note, and S06.A1XS is one of the codes named.

  • S06.2 Diffuse traumatic brain injury
    code, if applicable, for traumatic brain compression or herniation (S06.A-) names S06.A-, which includes this code
  • S06.3 Focal traumatic brain injury
    code, if applicable, for traumatic brain compression or herniation (S06.A-) names S06.A-, which includes this code
  • S06.5 Traumatic subdural hemorrhage
    code, if applicable, for traumatic brain compression or herniation (S06.A-) names S06.A-, which includes this code
  • S06.6 Traumatic subarachnoid hemorrhage
    code, if applicable, for traumatic brain compression or herniation (S06.A-) names S06.A-, which includes this code
  • S07 Crushing injury of head
    intracranial injuries (S06.-) names S06.-, which includes this code

Code Also 2

These codes say S06.A1XS may also be needed to fully describe the condition. The note gives no sequencing direction.

  • S01 Open wound of head
    intracranial injury (S06.-) names S06.-, which includes this code
  • S02 Fracture of skull and facial bones
    any associated intracranial injury (S06.-) names S06.-, which includes this code

Notes 1

These notes mention S06.A1XS.

  • S06 Intracranial injury
    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. names S06, which includes this code

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ073
Injury, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

Code History & ChangesHistory

Replacement S06.A1XS replaces the following previously assigned code(s):

  • S06.890D - Intcran inj w/o loss of consciousness, subs encntr
  • S06.890S - Oth intracranial injury w/o loss of consciousness, sequela
  • S06.891 - Intcran inj w loss of consciousness of 30 minutes or less
  • S06.891A - Intcran inj w LOC of 30 minutes or less, init
  • S06.891D - Intcran inj w LOC of 30 minutes or less, subs
  • S06.891S - Intcran inj w LOC of 30 minutes or less, sequela
  • S06.892 - Intcran inj w loss of consciousness of 31-59 min
  • S06.892A - Intcran inj w loss of consciousness of 31-59 min, init
  • S06.892D - Intcran inj w loss of consciousness of 31-59 min, subs
  • S06.892S - Intcran inj w loss of consciousness of 31-59 min, sequela
  • S06.893 - Intcran inj w loss of consciousness of 1-5 hrs 59 min
  • S06.893A - Intcran inj w loss of consciousness of 1-5 hrs 59 min, init
  • S06.893D - Intcran inj w loss of consciousness of 1-5 hrs 59 min, subs
  • S06.893S - Intcran inj w LOC of 1-5 hrs 59 min, sequela
  • S06.894 - Intcran inj w loss of consciousness of 6 hours to 24 hours
  • S06.894A - Intcran inj w LOC of 6 hours to 24 hours, init
  • S06.894D - Intcran inj w LOC of 6 hours to 24 hours, subs
  • S06.894S - Intcran inj w LOC of 6 hours to 24 hours, sequela
  • S06.895 - Intcran inj w loss of consciousness >24 hr w ret consc lev
  • S06.895A - Intcran inj w LOC >24 hr w ret consc lev, init
  • S06.895D - Intcran inj w LOC >24 hr w ret consc lev, subs
  • S06.895S - Intcran inj w LOC >24 hr w ret consc lev, sequela
  • S06.896 - Intcran inj w LOC >24 hr w/o ret consc w surv
  • S06.896A - Intcran inj w LOC >24 hr w/o ret consc w surv, init
  • S06.896D - Intcran inj w LOC >24 hr w/o ret consc w surv, subs
  • S06.896S - Intcran inj w LOC >24 hr w/o ret consc w surv, sequela
  • S06.897 - Intcran inj w LOC w death due to brain injury bf consc
  • S06.897A - Intcran inj w LOC w death due to brain injury bf consc, init
  • S06.898 - Intcran inj w LOC w death due to oth cause bf consc
  • S06.898A - Intcran inj w LOC w death due to oth cause bf consc, init
  • S06.899 - Intcran inj w loss of consciousness of unsp duration
  • S06.899A - Intcran inj w loss of consciousness of unsp duration, init
  • S06.899D - Intcran inj w loss of consciousness of unsp duration, subs
  • S06.899S - Intcran inj w LOC of unsp duration, sequela
FY 2022AddedAdded to the ICD-10-CM code setEffective October 1, 2021.
FY 2023–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S06.A1XSOverview

What is the ICD-10 code for traumatic brain compression with herniation, sequela?

The ICD-10-CM code for traumatic brain compression with herniation, sequela is S06.A1XS (sometimes written as S06A1XS). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is S06.A1XS (Traumatic brain compression with herniation) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report traumatic brain compression with herniation, sequela on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character S in S06.A1XS mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the traumatic brain compression with herniation itself has resolved, not the original event.

What MS-DRG does S06.A1XS group to?

On inpatient claims, traumatic brain compression with herniation, sequela maps to MS-DRG 914, 913, with relative weights from 0.9281 to 1.5448 depending on complications. Higher weights mean higher Medicare reimbursement.

Can S06.A1XS be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because traumatic brain compression with herniation, sequela describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Does S06.A1XS risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. S06.A1XS mapped to HCC 167 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 167 (Major Head Injury), ESRD (V21) category 167 (Major Head Injury), and ESRD (V24) category 167 (Major Head Injury).