ICD-10 Code M01.X79 – Direct infection of unspecified ankle and foot in infectious and parasitic diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M01.X79 – Direct infection of unspecified ankle and foot in infectious and parasitic diseases classified elsewhere
What it is
This code identifies a direct infection of the ankle or foot when the infection is caused by an infectious or parasitic disease classified elsewhere. Use it when the affected site is unspecified within the ankle and foot.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include localized pain, swelling, warmth, redness, and reduced function in the ankle or foot, with evidence that the infection is linked to another infectious or parasitic condition.
When to use this code
Use this code when the record documents direct infection involving the ankle and foot, but does not specify a more exact site. It is appropriate when the provider links the joint or soft tissue infection to an infectious or parasitic disease classified elsewhere. Check documentation for the underlying cause and the exact anatomic location.
Do not use for
Do not use this code for nonspecific foot pain, trauma, or routine skin infections without a documented direct infectious link. Do not use it when the ankle or foot site is specified more precisely and a different code is supported.
Coding tip
Code the underlying infectious or parasitic disease first when documented, and confirm that the ankle or foot infection is explicitly stated as direct.