2026 ICD-10-CM Diagnosis Code S91.301AUnspecified open wound, right foot, initial encounter

ICD-10-CM Codes›S00–T88›S90-S99›S91

ICD-10-CM S91.301A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S91.301A is a billable ICD-10-CM diagnosis code for unspecified open wound, right foot, 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 604 through 605, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Open wounds to limbs, initial encounter.

Code Identity

ICD-10-CM Code
S91.301A
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified open wound, right foot, initial encounter
Short Description
Unspecified open wound, right foot, initial encounter
Same as the full description in the CMS dataset.
Parent Code
S91.301
Unspecified open wound, right foot

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 CodeS91.301AUnspecified open wound, right foot, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Fracture of cuboid
  • Fracture of fifth metatarsal bone of right foot
  • Fracture of first metatarsal bone of right foot
  • Fracture of fourth metatarsal bone of right foot
  • Fracture of lateral cuneiform
  • Fracture of medial cuneiform
  • Fracture of navicular
  • Fracture of right calcaneum
  • Fracture of right talus
  • Fracture of second metatarsal bone of right foot
  • Fracture of third metatarsal bone of right foot
  • Open dislocation of right tarsal joint
  • Open fracture of calcaneus
  • Open fracture of cuboid bone of foot
  • Open fracture of cuboid bone of right foot
  • Open fracture of cuneiform bone of foot
  • Open fracture of fifth metatarsal bone
  • Open fracture of fifth metatarsal bone of right foot
  • Open fracture of first metatarsal bone
  • Open fracture of first metatarsal bone of right foot
  • Open fracture of fourth metatarsal bone
  • Open fracture of fourth metatarsal bone of right foot
  • Open fracture of lateral cuneiform bone of foot
  • Open fracture of lateral cuneiform bone of right foot
  • Open fracture of medial cuneiform bone of foot
  • Open fracture of medial cuneiform bone of right foot
  • Open fracture of metaphysis of fifth metatarsal bone
  • Open fracture of metaphysis of fifth metatarsal bone of right foot
  • Open fracture of metaphysis of first metatarsal bone
  • Open fracture of metaphysis of first metatarsal bone of right foot
  • Open fracture of metaphysis of metatarsal bone
  • Open fracture of metatarsal bone of right foot
  • Open fracture of navicular bone of foot
  • Open fracture of navicular bone of right foot
  • Open fracture of right ankle
  • Open fracture of right calcaneus
  • Open fracture of right foot
  • Open fracture of right talus
  • Open fracture of second metatarsal bone
  • Open fracture of second metatarsal bone of right foot
  • Open fracture of talus
  • Open fracture of tarsal bone of right foot
  • Open fracture of third metatarsal bone
  • Open fracture of third metatarsal bone of right foot
  • Open traumatic dislocation of joint of right foot
  • Open traumatic dislocation of tarsometatarsal joint
  • Open traumatic dislocation of tarsometatarsal joint of right foot
  • Open wound of right foot
  • Traumatic dislocation of tarsometatarsal joint

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 INJ012
Open wounds to limbs, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Foot Injuries and Disorders

Each of your feet has 26 bones, 33 joints, and more than 100 tendons, muscles, and ligaments. No wonder a lot of things can go wrong. Here are a few common problems:

Read the full article at MedlinePlus

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

Convert S91.301A to ICD-9-CMHistory

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

ICD-9-CM
892.0 Open wound of foot
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 S91.301AOverview

Is S91.301A (Unspecified open wound, right foot) a billable code?

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

What does the 7th character A in S91.301A mean?

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

What MS-DRG does S91.301A group to?

When unspecified open wound, right foot, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 604, 605, 963, 964, 965, with relative weights from 0.9160 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S91.301A?

Under the General Equivalence Mappings, unspecified open wound, right foot, initial encounter converts to ICD-9-CM 892.0 (open wound of foot). 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.