2026 ICD-10-CM Diagnosis Code S01.109AUnspecified open wound of unspecified eyelid and periocular area, initial encounter

ICD-10-CM Codes›S00–T88›S00-S09›S01

ICD-10-CM S01.109A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S01.109A is a billable ICD-10-CM diagnosis code for unspecified open wound of unspecified eyelid and periocular area, 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 124 through 125, 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 Open wounds of head and neck, initial encounter.

Code Identity

ICD-10-CM Code
S01.109A
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified open wound of unspecified eyelid and periocular area, initial encounter
Short Description
Unsp open wound of unsp eyelid and periocular area, init
Parent Code
S01.109
Unspecified open wound of unspecified eyelid and periocular area

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS00-S09Injuries to the head
CategoryS01Open wound of head
This CodeS01.109AUnspecified open wound of unspecified eyelid and periocular area, initial encounter

Code EditsBilling

Medicare Code Editor checks that affect claim validity for S01.109A.

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.

  • Avulsion of eyelid
  • Blow out fracture of orbit
  • Fracture of medial wall of orbit
  • Full thickness open wound of eyelid
  • Injury of eyebrow
  • Open blow out fracture of orbit
  • Open blow out fracture of orbital floor
  • Open fracture of medial wall of orbit
  • Open fracture of orbital portion of zygomatic bone
  • Open fracture of zygoma
  • Open wound of eyebrow
  • Open wound of eyelid
  • Open wound of ocular adnexa
  • Open wound of skin of eyelid
  • Orbitozygomatic fracture
  • Outer canthus finding
  • Partial thickness open wound of eyelid
  • Partial thickness skin loss
  • Periocular open wound
  • Traumatic avulsion of lateral canthus
  • Traumatic avulsion of medial canthus

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Open wound of head (S01). 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 INJ011
Open wounds of head and neck, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Eye Injuries

The structure of your face helps protect your eyes from injury. Still, injuries can damage your eye, sometimes severely enough that you could lose your vision. Most eye injuries are preventable. If you play sports or work in certain jobs, you may need protection.

Read the full article at MedlinePlus

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

Convert S01.109A to ICD-9-CMHistory

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

ICD-9-CM
870.9 Opn wnd ocular adnex 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 S01.109AOverview

Is S01.109A a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified open wound of unspecified eyelid and periocular area, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S01.109A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for unspecified open wound of unspecified eyelid and periocular area, such as an emergency visit or first evaluation.

What MS-DRG does S01.109A group to?

When unspecified open wound of unspecified eyelid and periocular area, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 124, 125, 963, 964, 965, with relative weights from 0.7678 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S01.109A?

Under the General Equivalence Mappings, unspecified open wound of unspecified eyelid and periocular area, initial encounter converts to ICD-9-CM 870.9 (opn wnd ocular adnex 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.