ICD-10 Code M05.1 – Rheumatoid lung disease with rheumatoid arthritis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.1 – Rheumatoid lung disease with rheumatoid arthritis
What it is
M05.1 identifies rheumatoid arthritis with associated lung involvement. Use it when the record shows rheumatoid disease affecting the lungs, not arthritis alone.
Clinical signs
Clinical features may include interstitial lung disease, pleural disease, pulmonary nodules, or other rheumatoid pulmonary manifestations. Confirm the lung involvement and its linkage to rheumatoid arthritis in the documentation.
When to use this code
Use M05.1 when the provider documents rheumatoid arthritis with rheumatoid lung disease or a similar causal relationship. This code supports cases where pulmonary findings are part of the rheumatoid disease picture. If the note only states arthritis or only states lung disease, check documentation before assigning it.
Do not use for
Do not use this code for rheumatoid arthritis without lung involvement, or for lung disease not linked to rheumatoid arthritis. Check documentation if the pulmonary condition is due to another cause.
Coding tip
Verify that the record explicitly connects the lung disease to rheumatoid arthritis before coding M05.1.