ICD-10 Code M05.171 – Rheumatoid lung disease with rheumatoid arthritis of right ankle and foot (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.171 – Rheumatoid lung disease 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 lung disease. Use it when the record clearly links both the joint disease and pulmonary involvement to rheumatoid arthritis.
Clinical signs
Typical findings include inflammatory pain, swelling, stiffness, and reduced function in the right ankle or foot. Rheumatoid lung disease may be documented as interstitial lung disease, pleural disease, or other pulmonary involvement; clinical features vary, refer to documentation.
When to use this code
Use M05.171 when the provider documents rheumatoid arthritis in the right ankle and foot and also states rheumatoid lung disease. You should code from the physician’s linkage, not from suspicion alone. If the laterality or lung involvement is unclear, check documentation.
Do not use for
Do not use this code for rheumatoid arthritis without lung involvement, or for lung disease not documented as rheumatoid in origin. Also avoid it when the affected joint is not the right ankle and foot.
Coding tip
Confirm both the pulmonary condition and the right-sided joint involvement are explicitly documented before assigning M05.171.