ICD-10 Code M02.39 – Reiter’s disease, multiple sites (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M02.39 – Reiter’s disease, multiple sites
What it is
M02.39 identifies Reiter’s disease, also called reactive arthritis, affecting multiple joints. Use it when the record shows this post-infectious inflammatory arthritis involves more than one site.
Clinical signs
Clinical features vary; refer to documentation. Typical findings include asymmetric joint pain, swelling, and stiffness, often with lower-limb involvement and a recent infection history.
When to use this code
Use this code when the provider documents Reiter’s disease or reactive arthritis and specifies multiple sites. It may fit notes describing polyarticular involvement after a genitourinary or gastrointestinal infection.
If the chart only says arthritis without the reactive arthritis diagnosis, check documentation before coding. Confirm that more than one joint or site is clearly involved.
Do not use for
Do not use this code for unspecified arthritis, isolated joint pain, or other inflammatory arthropathies without reactive arthritis documented. Check documentation if the condition is limited to one site.
Coding tip
Code M02.39 only when the record clearly supports reactive arthritis at multiple sites; otherwise, query for the exact diagnosis and site detail.