ICD-10 Code M05.079 – Felty’s syndrome, unspecified ankle and foot (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.079 – Felty’s syndrome, unspecified ankle and foot
What it is
M05.079 identifies Felty’s syndrome affecting an unspecified ankle and foot. It indicates rheumatoid arthritis with the Felty’s syndrome complication, but the ankle and foot site is not further specified.
Clinical signs
Clinical features vary; refer to documentation. Felty’s syndrome is commonly associated with long-standing rheumatoid arthritis, neutropenia, and splenomegaly, but you should code only what is documented.
When to use this code
Use this code when the record documents Felty’s syndrome and the provider specifies involvement of an unspecified ankle or foot. It is appropriate when the laterality or exact foot/ankle site is not stated. Check documentation if the note mentions rheumatoid arthritis without Felty’s syndrome, or if a more specific site is recorded.
Do not use for
Do not use this code for rheumatoid arthritis without Felty’s syndrome, or for ankle and foot pain alone. Check documentation if the condition is a different rheumatoid arthritis complication or a more specific ankle or foot code applies.
Coding tip
Verify that Felty’s syndrome is explicitly documented and that the ankle or foot site is unspecified before assigning M05.079.