2026 ICD-10-CM Diagnosis Code S06.820DInjury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, subsequent encounter

ICD-10-CM Codes›S00–T88›S00-S09›S06

ICD-10-CM S06.820D
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S06.820D is a billable ICD-10-CM diagnosis code for injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, 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 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
S06.820D
Billable Status
Yes — Valid for Submission
Code Describes
Injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, subsequent encounter
Short Description
Injury of l int carotid, intcr w/o LOC, subs
Parent Code
S06.820
Injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS00-S09Injuries to the head
CategoryS06Intracranial injury
This CodeS06.820DInjury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, subsequent encounter

Present on Admission (POA)Billing

S06.820D 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

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 S06.820D to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
V58.89 Other specfied aftercare
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S06.820DOverview

Is S06.820D a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, subsequent encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character D in S06.820D mean?

The final character D marks a subsequent encounter: use it for routine care while the injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness is healing, after active treatment has ended.

What MS-DRG does S06.820D group to?

When injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, subsequent encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 949, 950, with relative weights from 0.6277 to 1.1897 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S06.820D 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 injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, subsequent encounter on inpatient claims.

What is the ICD-9 equivalent of S06.820D?

Under the General Equivalence Mappings, injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, subsequent encounter converts to ICD-9-CM V58.89 (other specfied aftercare). The mapping is approximate, so confirm the match fits the documentation.

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.