ICD-10 Code M05.8 – Other rheumatoid arthritis with rheumatoid factor (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.8 – Other rheumatoid arthritis with rheumatoid factor
What it is
M05.8 identifies rheumatoid arthritis with rheumatoid factor when the record does not fit a more specific rheumatoid arthritis subtype. It signals an inflammatory autoimmune joint disease documented with rheumatoid factor positivity.
Clinical signs
Common findings include symmetric joint pain, swelling, stiffness, and reduced range of motion, especially in the hands and feet. Clinical features vary; refer to documentation for the specific joints and severity involved.
When to use this code
Use this code when the provider documents rheumatoid arthritis with rheumatoid factor but does not specify another M05 category. It may apply to records describing rheumatoid factor–positive disease without a clearer subtype. Check documentation if the chart also names another rheumatoid arthritis manifestation.
Do not use for
Do not use it for rheumatoid arthritis without rheumatoid factor, which is coded elsewhere. Do not assign it when the record supports a more specific rheumatoid arthritis code. Check documentation if the diagnosis wording is incomplete.
Coding tip
Match the code to the provider’s exact wording and avoid defaulting to M05.8 when a more specific rheumatoid arthritis code is documented.