ICD-10 Code M05.10 – Rheumatoid lung disease with rheumatoid arthritis of unspecified site (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.10 – Rheumatoid lung disease with rheumatoid arthritis of unspecified site
What it is
This code identifies rheumatoid arthritis complicated by lung involvement, when the affected joint site is not specified. Use it when documentation links the pulmonary disease to rheumatoid arthritis but does not name a specific joint location.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings may include interstitial lung disease, pulmonary nodules, pleural disease, or other rheumatoid pulmonary manifestations in a patient with rheumatoid arthritis.
When to use this code
Use M05.10 when the provider documents rheumatoid lung disease and rheumatoid arthritis, but the arthritis site is not identified. It is appropriate for records describing lung involvement as a manifestation of rheumatoid disease. If the note specifies a different rheumatoid arthritis site, code that more specific option instead.
Do not use for
Do not use this code if the record does not link the lung disease to rheumatoid arthritis. Also avoid it when the arthritis site is documented elsewhere and a more specific code applies; check documentation.
Coding tip
Confirm both the rheumatoid lung disease and the unspecified-site rheumatoid arthritis are documented before assigning M05.10.