ICD-10 Code M05.471 – Rheumatoid myopathy with rheumatoid arthritis of right ankle and foot (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.471 – Rheumatoid myopathy with rheumatoid arthritis of right ankle and foot
What it is
This code identifies rheumatoid arthritis affecting the right ankle and foot with associated rheumatoid myopathy. Use it when documentation links the muscle disorder to rheumatoid disease in that specific location.
Clinical signs
Typical findings include inflammatory joint pain, swelling, stiffness, and reduced function in the right ankle or foot. Clinical features vary; refer to documentation for evidence of rheumatoid myopathy, such as muscle weakness or myopathic involvement.
When to use this code
Use this code when the provider documents rheumatoid arthritis of the right ankle and foot and also states rheumatoid myopathy. It fits encounters where the right-sided ankle-foot involvement is clearly specified and the muscle condition is part of the diagnosis. Check documentation if the laterality or myopathy link is unclear.
Do not use for
Do not use it for rheumatoid arthritis without myopathy, or for involvement of another joint or side. Do not assign it when the record only says muscle pain or weakness without documented rheumatoid myopathy.
Coding tip
Verify both the rheumatoid myopathy and the right ankle-foot laterality in the provider note before assigning M05.471.