ICD-10 Code M05.042 – Felty’s syndrome, left hand (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.042 – Felty’s syndrome, left hand
What it is
This code identifies Felty’s syndrome affecting the left hand, a rheumatoid arthritis-related condition with joint involvement documented on the left side. Use it when the record clearly links Felty’s syndrome to the left hand.
Clinical signs
Clinical features vary; refer to documentation. Standard references describe Felty’s syndrome as rheumatoid arthritis with splenomegaly and neutropenia, and the hand may show chronic inflammatory joint changes.
When to use this code
Use this code when the provider documents Felty’s syndrome and specifies the left hand as the affected site. It is appropriate for encounters focused on left-hand manifestations of the syndrome or when laterality is clearly stated in the assessment.
If the note only says Felty’s syndrome without laterality, check documentation before assigning a side-specific code. Do not assume left hand from general rheumatoid arthritis language or from nonspecific hand pain.
Do not use for
Do not use this code for general Felty’s syndrome without left-hand specification, or for unrelated left-hand arthritis. Check documentation if the record describes another rheumatoid condition or an unspecified hand site.
Coding tip
Confirm both the syndrome and the left-hand laterality in the provider note before coding.