2026 ICD-10-CM Diagnosis Code S09.0XXAInjury of blood vessels of head, not elsewhere classified, initial encounter

ICD-10-CM Codes›S00–T88›S00-S09›S09

ICD-10-CM S09.0XXA
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S09.0XXA is a billable ICD-10-CM diagnosis code for injury of blood vessels of head, not elsewhere classified, 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 11 through 13, 913 through 914, 963 through 965. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 30 closely related codes. Coders also document this condition as injury of artery of head and neck. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury to blood vessels, initial encounter.

Code Identity

ICD-10-CM Code
S09.0XXA
Billable Status
Yes — Valid for Submission
Code Describes
Injury of blood vessels of head, not elsewhere classified, initial encounter
Short Description
Injury of blood vessels of head, NEC, init
Parent Code
S09.0
Injury of blood vessels of head, not elsewhere classified

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS00-S09Injuries to the head
CategoryS09Other and unspecified injuries of head
This CodeS09.0XXAInjury of blood vessels of head, not elsewhere classified, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Injury of artery of head and neck
  • Injury of blood vessel of head and/or neck
  • Injury of extracranial vessel of head
  • Injury of multiple blood vessels of head
  • Injury of multiple blood vessels of head and/or neck
  • Injury of vein of head and neck
  • Traumatic injury of blood vessel of head

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Other and unspecified injuries of head (S09). 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 INJ016
Injury to blood vessels, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Head Injuries

Chances are you've bumped your head before. Often, the injury is minor because your skull is hard and it protects your brain. But other head injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert S09.0XXA to ICD-9-CMHistory

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

ICD-9-CM
900.89 Inj head/neck vessel NEC
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 S09.0XXAOverview

Is S09.0XXA (Injury of blood vessels of head, not elsewhere classified) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report injury of blood vessels of head, not elsewhere classified, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S09.0XXA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for injury of blood vessels of head, not elsewhere classified, such as an emergency visit or first evaluation.

What MS-DRG does S09.0XXA group to?

When injury of blood vessels of head, not elsewhere classified, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 11, 12, 13, 913, 914, 963, 964, 965, with relative weights from 0.8855 to 5.4541 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S09.0XXA a CC or MCC?

CMS lists S09.0XXA as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 30 closely related codes in its exclusion list.

What is the ICD-9 equivalent of S09.0XXA?

Under the General Equivalence Mappings, injury of blood vessels of head, not elsewhere classified, initial encounter converts to ICD-9-CM 900.89 (inj head/neck vessel NEC). The mapping is approximate, so confirm the match fits the documentation.