ICD-10 Code M05.47 – Rheumatoid myopathy with rheumatoid arthritis of ankle and foot (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.47 – Rheumatoid myopathy with rheumatoid arthritis of ankle and foot
What it is
This code identifies rheumatoid arthritis affecting the ankle and foot, with associated rheumatoid myopathy. Use it when the record shows both inflammatory joint disease and muscle involvement in these areas.
Clinical signs
Findings may include painful, swollen, stiff ankle or foot joints and reduced function from rheumatoid disease. Muscle weakness or myopathic changes should be documented; clinical features vary, so refer to documentation.
When to use this code
Use this code when the provider documents rheumatoid arthritis of the ankle and foot together with rheumatoid myopathy. It fits encounters where both the joint and muscle components are part of the confirmed diagnosis. Check documentation if laterality, site detail, or myopathy wording is unclear.
Do not use for
Do not use it for rheumatoid arthritis of the ankle and foot without myopathy, or for non-rheumatoid muscle pain or weakness. If the chart does not clearly link the myopathy to rheumatoid disease, check documentation.
Coding tip
Confirm that the provider explicitly documents both rheumatoid myopathy and ankle-foot involvement before assigning M05.47.