ICD-10 Code M05.871 – Other rheumatoid arthritis with rheumatoid factor of right ankle and foot (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.871 – Other rheumatoid arthritis with rheumatoid factor of right ankle and foot
What it is
This code identifies rheumatoid arthritis with rheumatoid factor affecting the right ankle and foot, when the condition does not fit a more specific rheumatoid arthritis category. Use it for documented inflammatory joint disease in that location.
Clinical signs
Common findings include chronic joint pain, swelling, stiffness, and reduced range of motion in the right ankle or foot. Clinical features vary; refer to documentation, and confirm rheumatoid factor positivity when recorded.
When to use this code
Use this code when the provider documents rheumatoid arthritis with rheumatoid factor involving the right ankle and foot, and no more specific rheumatoid arthritis code applies. It is appropriate for active disease noted in clinic, hospital, or specialist records. Check documentation for laterality and joint site before assigning.
Do not use for
Do not use it for rheumatoid arthritis without rheumatoid factor, other joints, or left-sided involvement. Check documentation if the record describes an unspecified inflammatory arthritis or another diagnosis.
Coding tip
Verify both the rheumatoid factor association and the right ankle/foot location in the provider’s note before coding.