ICD-10 Code M05.771 – Rheumatoid arthritis with rheumatoid factor of right ankle and foot without organ or systems involvement (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.771 – Rheumatoid arthritis with rheumatoid factor of right ankle and foot without organ or systems involvement
What it is
This code identifies rheumatoid arthritis affecting the right ankle and foot, with rheumatoid factor present and no documented organ or system involvement. Use it when the record specifies this joint location and seropositive disease.
Clinical signs
Typical findings include inflammatory joint pain, swelling, stiffness, and reduced motion in the right ankle or foot. Clinical features vary; refer to documentation, especially for evidence of rheumatoid factor positivity and absence of extra-articular disease.
When to use this code
Use this code when the clinician documents rheumatoid arthritis with rheumatoid factor involving the right ankle and foot only. It fits seropositive disease limited to these joints, without mention of organ or system involvement. Check documentation if laterality or systemic involvement is unclear.
Do not use for
Do not use this code for rheumatoid arthritis of another joint, unspecified laterality, or rheumatoid arthritis without rheumatoid factor. Do not assign it if the record documents organ or system involvement.
Coding tip
Confirm both laterality and seropositive status in the note before assigning M05.771.