2027 ICD-10-CM Diagnosis Code S99Other and unspecified injuries of ankle and foot

ICD-10-CM Codes›S00–T88›S90-S99›S99

ICD-10-CM S99
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S99 is a non-billable ICD-10-CM category code for other and unspecified injuries of ankle and foot, so it cannot be submitted on claims. Use a more specific code from this category instead, such as S99.001A, S99.001B, S99.001D, and S99.001G.

Code Identity

ICD-10-CM Code
S99
Billable Status
No — Non-Billable Category
Code Describes
Other and unspecified injuries of ankle and foot
Short Description
Other and unspecified injuries of ankle and foot
Same as the full description in the CMS dataset.
Chapter
S90-S99
Injuries to the ankle and foot

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS90-S99Injuries to the ankle and foot
CategoryS99Other and unspecified injuries of ankle and foot
This CodeS99Other and unspecified injuries of ankle and foot

Specific Coding for Other and unspecified injuries of ankle and footOverview

Non-specific codes like S99 require more characters. Use one of these billable codes instead:

  • S99.0 for Physeal fracture of calcaneus

  • S99.00 for Unspecified physeal fracture of calcaneus

  • S99.01 for Salter-Harris Type I physeal fracture of calcaneus

  • S99.02 for Salter-Harris Type II physeal fracture of calcaneus

  • S99.03 for Salter-Harris Type III physeal fracture of calcaneus

  • S99.04 for Salter-Harris Type IV physeal fracture of calcaneus

  • S99.09 for Other physeal fracture of calcaneus

  • S99.1 for Physeal fracture of metatarsal

  • S99.10 for Unspecified physeal fracture of metatarsal

  • S99.11 for Salter-Harris Type I physeal fracture of metatarsal

  • S99.12 for Salter-Harris Type II physeal fracture of metatarsal

  • S99.13 for Salter-Harris Type III physeal fracture of metatarsal

  • S99.14 for Salter-Harris Type IV physeal fracture of metatarsal

  • S99.19 for Other physeal fracture of metatarsal

  • S99.2 for Physeal fracture of phalanx of toe

  • S99.20 for Unspecified physeal fracture of phalanx of toe

  • S99.21 for Salter-Harris Type I physeal fracture of phalanx of toe

  • S99.22 for Salter-Harris Type II physeal fracture of phalanx of toe

  • S99.23 for Salter-Harris Type III physeal fracture of phalanx of toe

  • S99.24 for Salter-Harris Type IV physeal fracture of phalanx of toe

  • S99.29 for Other physeal fracture of phalanx of toe

  • S99.8 for Other specified injuries of ankle and foot

  • S99.81 for Other specified injuries of ankle

  • S99.82 for Other specified injuries of foot

  • S99.9 for Unspecified injury of ankle and foot

  • S99.91 for Unspecified injury of ankle

  • S99.92 for Unspecified injury of foot

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Other and unspecified injuries of ankle and foot (S99). 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 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to S99: its own notes plus those printed at block S90-S99 and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block S90-S99 Injuries to the ankle and foot applies to 3,324 codes
  • burns and corrosions (T20-T32)
  • fracture of ankle and malleolus (S82.-)
  • frostbite (T33-T34)
  • insect bite or sting, venomous (T63.4)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Notes

General instructions on how these codes are used.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name S99, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming S99: its condition is not part of those codes, and both may be reported when the patient has both.

  • S89 Other and unspecified injuries of lower leg
    other and unspecified injuries of ankle and foot (S99.-)

Patient EducationClinical

Ankle Injuries and Disorders

Your ankle bone and the ends of your two lower leg bones make up the ankle joint. Your ligaments, which connect bones to one another, stabilize and support it. Your muscles and tendons move it.

Read the full article at MedlinePlus

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

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S99Overview

What is the ICD-10 code for other and unspecified injuries of ankle and foot?

S99 is the ICD-10-CM category for other and unspecified injuries of ankle and foot, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is S99 (Other and unspecified injuries of ankle and foot) a billable code?

No. This is a category header that groups the codes for other and unspecified injuries of ankle and foot, and headers cannot be submitted on claims. Claims for other and unspecified injuries of ankle and foot need a more specific code from this category, such as S99.001A, S99.001B, and S99.001D.