2024 ICD-10-CM Diagnosis Code S99

Other and unspecified injuries of ankle and foot

ICD-10-CM Code:
S99
ICD-10 Code for:
Other and unspecified injuries of ankle and foot
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Injury, poisoning and certain other consequences of external causes
    (S00–T88)
    • Injuries to the ankle and foot
      (S90-S99)
      • Other and unspecified injuries of ankle and foot
        (S99)

S99 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of other and unspecified injuries of ankle and foot. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Unspecified diagnosis codes like S99 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Specific Coding Applicable to Other and unspecified injuries of ankle and foot

Non-specific codes like S99 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for other and unspecified injuries of ankle and foot:

  • S99.0 for Physeal fracture of calcaneus - NON-BILLABLE CODE

  • S99.00 for Unspecified physeal fracture of calcaneus - NON-BILLABLE CODE

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

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

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

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

  • S99.09 for Other physeal fracture of calcaneus - NON-BILLABLE CODE

  • S99.1 for Physeal fracture of metatarsal - NON-BILLABLE CODE

  • S99.10 for Unspecified physeal fracture of metatarsal - NON-BILLABLE CODE

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

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

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

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

  • S99.19 for Other physeal fracture of metatarsal - NON-BILLABLE CODE

  • S99.2 for Physeal fracture of phalanx of toe - NON-BILLABLE CODE

  • S99.20 for Unspecified physeal fracture of phalanx of toe - NON-BILLABLE CODE

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

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

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

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

  • S99.29 for Other physeal fracture of phalanx of toe - NON-BILLABLE CODE

  • S99.8 for Other specified injuries of ankle and foot - NON-BILLABLE CODE

  • S99.81 for Other specified injuries of ankle - NON-BILLABLE CODE

  • S99.82 for Other specified injuries of foot - NON-BILLABLE CODE

  • S99.9 for Unspecified injury of ankle and foot - NON-BILLABLE CODE

  • S99.91 for Unspecified injury of ankle - NON-BILLABLE CODE

  • S99.92 for Unspecified injury of foot - NON-BILLABLE CODE

Coding Guidelines

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 aplicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Patient Education


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.

The most common ankle problems are sprains and fractures (broken bones). A sprain is an injury to the ligaments. It may take a few weeks to many months to heal completely. A fracture is a break in a bone. You can also injure other parts of the ankle such as tendons, which join muscles to bone, and cartilage, which cushions your joints. Ankle sprains and fractures are common sports injuries.


[Learn More in MedlinePlus]

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:

  • Bunions - hard, painful bumps on the big toe joint
  • Corns and calluses - thickened skin from friction or pressure
  • Plantar warts - warts on the soles of your feet
  • Fallen arches - also called flat feet

Ill-fitting shoes often cause these problems. Aging and being overweight also increase your chances of having foot problems.


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.