2026 ICD-10-CM Diagnosis Code S06.6XAATraumatic subarachnoid hemorrhage with loss of consciousness status unknown, initial encounter

ICD-10-CM Codes›S00–T88›S00-S09›S06

ICD-10-CM S06.6XAA
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S06.6XAA is a billable ICD-10-CM diagnosis code for traumatic subarachnoid hemorrhage with loss of consciousness status unknown, 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 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Traumatic brain injury (TBI); concussion, initial encounter.

Code Identity

ICD-10-CM Code
S06.6XAA
Billable Status
Yes — Valid for Submission
Code Describes
Traumatic subarachnoid hemorrhage with loss of consciousness status unknown, initial encounter
Short Description
Traum subrac hem with LOC status unknown, initial encounter
Parent Code
S06.6XA
Traumatic subarachnoid hemorrhage with loss of consciousness status unknown

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS00-S09Injuries to the head
CategoryS06Intracranial injury
This CodeS06.6XAATraumatic subarachnoid hemorrhage with loss of consciousness status unknown, initial encounter

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 INJ008
Traumatic brain injury (TBI); concussion, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Code History & ChangesHistory

Replacement S06.6XAA replaces the following previously assigned code(s):

  • S06.6X9A - Traum subrac hem w LOC of unsp duration, init
FY 2023AddedAdded to the ICD-10-CM code setEffective October 1, 2022.
FY 2024–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S06.6XAAOverview

Is S06.6XAA a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report traumatic subarachnoid hemorrhage with loss of consciousness status unknown, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S06.6XAA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for traumatic subarachnoid hemorrhage with loss of consciousness status unknown, such as an emergency visit or first evaluation.

What MS-DRG does S06.6XAA group to?

When traumatic subarachnoid hemorrhage with loss of consciousness status unknown, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 963, 964, 965, with relative weights from 0.9405 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

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.