2026 ICD-10-CM Diagnosis Code S91.159SOpen bite of unspecified toe(s) without damage to nail, sequela

ICD-10-CM Codes›S00–T88›S90-S99›S91

ICD-10-CM S91.159S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S91.159S is a billable ICD-10-CM diagnosis code for open bite of unspecified toe(s) without damage to nail, 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 604 through 605. 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
S91.159S
Billable Status
Yes — Valid for Submission
Code Describes
Open bite of unspecified toe(s) without damage to nail, sequela
Short Description
Open bite of unsp toe(s) without damage to nail, sequela
Parent Code
S91.159
Open bite of unspecified toe(s) without damage to nail

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS90-S99Injuries to the ankle and foot
CategoryS91Open wound of ankle, foot and toes
This CodeS91.159SOpen bite of unspecified toe(s) without damage to nail, sequela

Present on Admission (POA)Billing

S91.159S 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.

  • Animal bite of toe
  • Dog bite of foot
  • Dog bite of toe
  • Human bite of foot
  • Human bite of toe
  • Open bite of toe
  • Open bite wound of left foot
  • Open bite wound of right foot
  • Open wound of left foot due to animal bite
  • Open wound of right foot due to animal bite
  • Open wound of toe of left foot due to animal bite
  • Open wound of toe of right foot due to animal bite

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Open wound of ankle, foot and toes (S91). 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

Animal Bites

Wild animals usually avoid people. They might attack, however, if they feel threatened, are sick, or are protecting their young or territory. Attacks by pets are more common. Animal bites rarely are life-threatening, but if they become infected, you can develop serious medical problems.

Read the full article at MedlinePlus

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

Convert S91.159S to ICD-9-CMHistory

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

ICD-9-CM
906.1 Late eff open wnd extrem
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 S91.159SOverview

Is S91.159S (Open bite of unspecified toe(s) without damage to nail) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report open bite of unspecified toe(s) without damage to nail, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in S91.159S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the open bite of unspecified toe(s) without damage to nail itself has resolved, not the original event.

What MS-DRG does S91.159S group to?

When open bite of unspecified toe(s) without damage to nail, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 604, 605, with relative weights from 0.9160 to 1.4721 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S91.159S 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 open bite of unspecified toe(s) without damage to nail, sequela on inpatient claims.

What is the ICD-9 equivalent of S91.159S?

Under the General Equivalence Mappings, open bite of unspecified toe(s) without damage to nail, sequela converts to ICD-9-CM 906.1 (late eff open wnd extrem). 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.