2026 ICD-10-CM Diagnosis Code S06.33AAContusion and laceration of cerebrum, unspecified, with loss of consciousness status unknown, initial encounter

ICD-10-CM Codes›S00–T88›S00-S09›S06

ICD-10-CM S06.33AA
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S06.33AA is a billable ICD-10-CM diagnosis code for contusion and laceration of cerebrum, unspecified, 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. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Traumatic brain injury (TBI); concussion, initial encounter.

Code Identity

ICD-10-CM Code
S06.33AA
Billable Status
Yes — Valid for Submission
Code Describes
Contusion and laceration of cerebrum, unspecified, with loss of consciousness status unknown, initial encounter
Short Description
Contus/lac cereb, with LOC status unknown, initial encounter
Parent Code
S06.33A
Contusion and laceration of cerebrum, unspecified, 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 CodeS06.33AAContusion and laceration of cerebrum, unspecified, with loss of consciousness status unknown, initial encounter

Code EditsBilling

Medicare Code Editor checks that affect claim validity for S06.33AA.

Unspecified codes
Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Brain injury with open intracranial wound AND concussion
  • Cerebral cortex laceration with concussion
  • Contusion and laceration of cerebrum
  • Contusion of cerebral cortex
  • Cortex laceration
  • Cortex laceration and contusion
  • Cortex laceration with open intracranial wound
  • Cortex laceration with open intracranial wound AND concussion
  • Focal brain laceration
  • Focal laceration of cerebrum
  • Laceration of cerebrum

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

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.

Code History & ChangesHistory

Replacement S06.33AA replaces the following previously assigned code(s):

  • S06.339A - Contus/lac cereb, 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 S06.33AAOverview

Is S06.33AA a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report contusion and laceration of cerebrum, unspecified, 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 S06.33AA mean?

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

What MS-DRG does S06.33AA group to?

When contusion and laceration of cerebrum, unspecified, 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.