ICD-10 Code M05.469 – Rheumatoid myopathy with rheumatoid arthritis of unspecified knee (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.469 – Rheumatoid myopathy with rheumatoid arthritis of unspecified knee
What it is
This code identifies rheumatoid arthritis affecting an unspecified knee, with associated rheumatoid myopathy. It indicates inflammatory joint disease plus muscle involvement in the same limb region.
Clinical signs
Findings may include knee pain, swelling, stiffness, and reduced range of motion, along with muscle weakness or wasting related to rheumatoid disease. Clinical features vary; refer to documentation.
When to use this code
Use this code when the record clearly documents rheumatoid arthritis of the knee and rheumatoid myopathy, but does not specify right or left knee. It is appropriate when the provider links the muscle disorder to the rheumatoid condition. Check documentation if the knee laterality is stated elsewhere.
Do not use for
Do not use this code for rheumatoid arthritis without myopathy, or for myopathy from another cause. If the knee side is documented, choose the laterality-specific code instead.
Coding tip
Confirm both the rheumatoid myopathy and the unspecified knee in the provider note before assigning M05.469.