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ICD-10-CM 2027

ICD-10 code for ankle injury

S99.91

Unspecified injury of ankle

Header — needs a more specific code

From the official ICD-10-CM alphabetic index entry “Injury › ankle”. Page updated September 29, 2026.

About coding ankle injury

The ICD-10-CM code for ankle injury is S99.91 (Unspecified injury of ankle). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on S99.91.

Within S99.9 (unspecified injury of ankle and foot), S99.91 is specifically for unspecified injury of ankle. Related codes cover foot (S99.92).

Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

More specific ankle injury codes (official index)

  • contusion
  • dislocation
  • fracture
  • nerve
  • open
  • specified type NEC S99.81 — Other specified injuries of ankle
  • sprain
  • superficial

Common questions about ankle injury ICD-10 codes

What is the ICD-10 code for ankle injury?

S99.91 — Unspecified injury of ankle (a header code; report a more specific subcode). More specific codes apply when the documentation supports them: S99.81.

Is S99.91 billable?

No. S99.91 is a header code. Report one of its more specific subcodes instead.