ICD-10 Code M05.869 – Other rheumatoid arthritis with rheumatoid factor of unspecified knee (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.869 – Other rheumatoid arthritis with rheumatoid factor of unspecified knee
What it is
This code identifies rheumatoid arthritis with rheumatoid factor involvement affecting an unspecified knee. Use it when the record documents rheumatoid arthritis and the knee is involved, but laterality is not stated.
Clinical signs
Typical findings include chronic inflammatory joint pain, swelling, stiffness, and reduced range of motion. Clinical features vary; refer to documentation for the specific knee and rheumatoid factor evidence.
When to use this code
Use this code when the provider documents rheumatoid arthritis with rheumatoid factor and names the knee without specifying right or left. It also fits when the note supports RA involvement of a knee joint and no more specific site is recorded. If the chart names another joint or a different RA type, choose a different code.
Do not use for
Do not use it for rheumatoid arthritis without rheumatoid factor, or for knee pain alone. Check documentation if laterality is known, because an unspecified knee code is not the best choice when the record is more specific.
Coding tip
Confirm both the rheumatoid factor association and the knee site before assigning M05.869.