ICD-10 Code M05.169 – Rheumatoid lung disease with rheumatoid arthritis of unspecified knee (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.169 – Rheumatoid lung disease with rheumatoid arthritis of unspecified knee
What it is
This code identifies rheumatoid arthritis affecting an unspecified knee together with rheumatoid lung disease. Use it when the record links both the joint disease and lung involvement to rheumatoid arthritis.
Clinical signs
Typical findings may include knee pain, swelling, stiffness, and reduced motion plus pulmonary involvement such as cough or dyspnea. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents rheumatoid arthritis in an unspecified knee and separately documents rheumatoid lung disease as related to the same condition. The knee laterality is not specified, so do not assume right or left. Check documentation if the lung disease is not clearly attributed to rheumatoid arthritis.
Do not use for
Do not use this code if the lung disease is unrelated to rheumatoid arthritis or if the knee involvement is documented as a different joint. Do not assign it when the record specifies a different knee laterality code.
Coding tip
Verify that the provider explicitly connects the lung disease to rheumatoid arthritis before assigning M05.169.