ICD-10 Code M05.742 – Rheumatoid arthritis with rheumatoid factor of left hand without organ or systems involvement (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.742 – Rheumatoid arthritis with rheumatoid factor of left hand without organ or systems involvement
What it is
This code identifies rheumatoid arthritis with a positive rheumatoid factor affecting the left hand, without documented involvement of organs or other body systems. Use it when the condition is limited to the hand and the record supports rheumatoid factor positivity.
Clinical signs
Typical findings include inflammatory pain, swelling, stiffness, and reduced motion in the left hand joints. Clinical features vary; refer to documentation for evidence of rheumatoid factor positivity and localized joint involvement.
When to use this code
Use M05.742 when the provider documents rheumatoid arthritis with rheumatoid factor affecting the left hand only. The note should support a left-hand site and no organ or systems involvement. If the documentation is unclear, check documentation before assigning the code.
Do not use for
Do not use this code if rheumatoid factor is not documented, if the right hand or another site is involved, or if organ/system involvement is present. For uncertain laterality or extent, check documentation.
Coding tip
Confirm both the positive rheumatoid factor and the left-hand location in the assessment or problem list before coding.