ICD-10 Code M05.061 – Felty’s syndrome, right knee (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.061 – Felty’s syndrome, right knee
What it is
M05.061 identifies Felty’s syndrome affecting the right knee. It indicates a rheumatoid arthritis-related condition documented for that joint, so you should code the site exactly as recorded.
Clinical signs
Clinical features vary; refer to documentation. In standard references, Felty’s syndrome is associated with rheumatoid arthritis and may include splenomegaly and neutropenia, but joint-specific findings should be confirmed in the record.
When to use this code
Use this code when the provider documents Felty’s syndrome involving the right knee. It is appropriate when the diagnosis is clearly linked to that joint and laterality is specified.
If the note mentions Felty’s syndrome without a site, or the knee side is not stated, check documentation before assigning this code. Do not assume laterality from other joint findings.
Do not use for
Do not use this code for unspecified knee involvement or for rheumatoid arthritis without Felty’s syndrome. Check documentation if the record describes another joint or only general systemic features.
Coding tip
Verify both the syndrome and the right-knee laterality before coding; if either is missing, query the provider.