2026 ICD-10-CM Diagnosis Code S09.90XSUnspecified injury of head, sequela

ICD-10-CM Codes›S00–T88›S00-S09›S09

ICD-10-CM S09.90XS
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S09.90XS is a billable ICD-10-CM diagnosis code for unspecified injury of head, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 913 through 914. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.

Code Identity

ICD-10-CM Code
S09.90XS
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified injury of head, sequela
Short Description
Unspecified injury of head, sequela
Same as the full description in the CMS dataset.
Parent Code
S09.90
Unspecified injury of head

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS00-S09Injuries to the head
CategoryS09Other and unspecified injuries of head
This CodeS09.90XSUnspecified injury of head, sequela

Present on Admission (POA)Billing

S09.90XS is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bleeding from nose
  • Chorea due to and following injury of head
  • Chorea due to injury of head
  • Chorea following injury
  • Closed injury of head
  • Closed wound of head
  • Cranial cerebrospinal fluid leak
  • Dementia due to and following injury of head
  • Dystonia due to head injury
  • Friction alopecia
  • Head and neck injury
  • Headache due to injury of head and neck
  • Hemichorea
  • Hemichorea due to head injury
  • Injury of back of head
  • Injury of forehead
  • Injury of head
  • Injury of head and/or neck
  • Injury of head with otorrhagia
  • Injury of head with rhinorrhagia
  • Injury of upper respiratory tract
  • Language disorder associated with thought disorder
  • Leak of cranial cerebrospinal fluid due to and following injury of head
  • Major head injury
  • Metal foreign body in forehead
  • Minor head injury
  • Moderate head injury
  • Multiple injuries of bone of cranium
  • Multiple injuries of head
  • Multiple injuries of head and chest
  • Multiple injuries of thorax
  • Non-accidental injury
  • Non-accidental injury to child
  • Non-accidental traumatic head injury to child
  • Parkinsonism due to and following injury of head
  • Posttraumatic headache
  • Post-traumatic mutism
  • Scalp injury
  • Sequelae of injuries of head
  • Traumatic alopecia
  • Traumatic epistaxis
  • Vertigo preceded by head injury
  • Wig friction

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 INJ073
Injury, sequela
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 S09.90XS to ICD-9-CMHistory

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

ICD-9-CM
908.9 Late effect injury NOS
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 S09.90XSOverview

Is S09.90XS (Unspecified injury of head) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified injury of head, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in S09.90XS mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the unspecified injury of head itself has resolved, not the original event.

What MS-DRG does S09.90XS group to?

When unspecified injury of head, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 913, 914, with relative weights from 0.8855 to 1.6346 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S09.90XS 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 unspecified injury of head, sequela on inpatient claims.

What is the ICD-9 equivalent of S09.90XS?

Under the General Equivalence Mappings, unspecified injury of head, sequela converts to ICD-9-CM 908.9 (late effect injury NOS). 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.