2026 ICD-10-CM Diagnosis Code S06.A1XDTraumatic brain compression with herniation, subsequent encounter

ICD-10-CM Codes›S00–T88›S00-S09›S06

ICD-10-CM S06.A1XD
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S06.A1XD is a billable ICD-10-CM diagnosis code for traumatic brain compression with herniation, subsequent encounter. The 7th character D marks it as a subsequent encounter code, used during routine care in the healing or recovery phase. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 949 through 950. The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Traumatic brain injury (TBI); concussion, subsequent encounter.

Code Identity

ICD-10-CM Code
S06.A1XD
Billable Status
Yes — Valid for Submission
Code Describes
Traumatic brain compression with herniation, subsequent encounter
Short Description
Traumatic brain compression with herniation, subs
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.A1XDTraumatic brain compression with herniation, subsequent encounter

Code EditsBilling

Medicare Code Editor checks that affect claim validity for S06.A1XD.

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.A1XD is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

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 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

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

CCSR INJ045
Traumatic brain injury (TBI); concussion, subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Code History & ChangesHistory

Replacement S06.A1XD replaces the following previously assigned code(s):

  • S06.890D - Intcran inj w/o loss of consciousness, subs encntr
  • S06.899D - Intcran inj w loss of consciousness of unsp duration, subs
FY 2022AddedAdded to the ICD-10-CM code setEffective October 1, 2021.
FY 2023–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S06.A1XDOverview

Is S06.A1XD (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, subsequent encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character D in S06.A1XD mean?

The final character D marks a subsequent encounter: use it for routine care while the traumatic brain compression with herniation is healing, after active treatment has ended.

What MS-DRG does S06.A1XD group to?

On inpatient claims, traumatic brain compression with herniation, subsequent encounter maps to MS-DRG 949, 950, with relative weights from 0.6277 to 1.1897 depending on complications. Higher weights mean higher Medicare reimbursement.

Can S06.A1XD be a principal diagnosis?

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

Is S06.A1XD exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for traumatic brain compression with herniation, subsequent encounter on inpatient claims.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.