ICD-10 Code M05.579 – Rheumatoid polyneuropathy with rheumatoid arthritis of unspecified ankle and foot (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.579 – Rheumatoid polyneuropathy with rheumatoid arthritis of unspecified ankle and foot
What it is
This code identifies rheumatoid arthritis affecting an unspecified ankle and foot, with associated rheumatoid polyneuropathy. Use it when the record links both the joint disease and nerve involvement to rheumatoid arthritis.
Clinical signs
Typical findings include inflammatory joint pain, swelling, stiffness, and reduced function in the ankle or foot. Neuropathy may cause numbness, tingling, burning pain, or weakness; clinical features vary, refer to documentation.
When to use this code
Use this code when the provider documents rheumatoid arthritis in an unspecified ankle and foot and also documents rheumatoid polyneuropathy. The neuropathy must be associated with the rheumatoid disease, not listed as a separate unrelated condition. If the laterality or specific joint is documented elsewhere, code that level of detail instead.
Do not use for
Do not use it for rheumatoid arthritis without nerve involvement, or for neuropathy from diabetes, compression, trauma, or other causes. Check documentation if the ankle, foot, or neuropathy relationship is unclear.
Coding tip
Verify that the note explicitly connects the neuropathy to rheumatoid arthritis before assigning M05.579.