ICD-10 Code M05.649 – Rheumatoid arthritis of unspecified hand with involvement of other organs and systems (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.649 – Rheumatoid arthritis of unspecified hand with involvement of other organs and systems
What it is
This code identifies rheumatoid arthritis affecting an unspecified hand, with documented involvement of other organs or body systems. Use it when the record confirms rheumatoid disease and extra-articular involvement, but the hand side is not specified.
Clinical signs
Typical findings include inflammatory joint pain, swelling, stiffness, and reduced hand function. Clinical features vary; refer to documentation for the specific extra-articular organ or system involvement.
When to use this code
Use this code when the provider documents rheumatoid arthritis in an unspecified hand and also notes involvement beyond the joints, such as systemic or organ manifestations. It is appropriate when laterality is not stated and the record supports rheumatoid disease with extra-articular involvement.
If the note only says rheumatoid arthritis of the hand without systemic involvement, check documentation for a more specific code. Code selection should match the documented site and extent of disease.
Do not use for
Do not use this code for rheumatoid arthritis without organ or system involvement, or when the affected hand is clearly specified elsewhere. Check documentation if the record describes another inflammatory arthritis or an unspecified arthropathy.
Coding tip
Confirm both elements in the note: unspecified hand and involvement of other organs or systems.