ICD-10 Code M05.121 – Rheumatoid lung disease with rheumatoid arthritis of right elbow (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.121 – Rheumatoid lung disease with rheumatoid arthritis of right elbow
What it is
This code identifies rheumatoid arthritis affecting the right elbow together with rheumatoid lung disease. Use it when the record shows both the joint involvement and pulmonary manifestation linked to rheumatoid arthritis.
Clinical signs
Typical findings include inflammatory arthritis of the right elbow plus evidence of rheumatoid lung involvement. Clinical features vary; refer to documentation for the specific pulmonary diagnosis, such as interstitial or pleural disease.
When to use this code
Use this code when the provider documents rheumatoid arthritis in the right elbow and also specifies rheumatoid lung disease. The lung condition must be attributed to rheumatoid arthritis, not listed as an unrelated respiratory disorder. Check documentation if the laterality or pulmonary manifestation is unclear.
Do not use for
Do not use it for rheumatoid arthritis without lung involvement, or for lung disease not linked to rheumatoid arthritis. If the elbow side is not right, or the record does not confirm the pulmonary association, choose the appropriate code instead.
Coding tip
Verify both the laterality and the documented rheumatoid lung manifestation before assigning M05.121.