ICD-10 Code M02.379 – Reiter’s disease, unspecified ankle and foot (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M02.379 – Reiter’s disease, unspecified ankle and foot
What it is
This code identifies Reiter’s disease, also called reactive arthritis, affecting the ankle and foot without a more specific side or site. Use it when the record documents this diagnosis but does not specify laterality or a more detailed joint.
Clinical signs
Typical findings include joint pain, swelling, and stiffness in the ankle or foot, often with an inflammatory pattern. Clinical features vary; refer to documentation for the exact joints and any associated extra-articular findings.
When to use this code
Use this code when the provider documents Reiter’s disease or reactive arthritis involving the ankle and foot, and the chart does not identify the right or left side. It also fits when the ankle and foot are named together but no more specific code is supported. Check documentation if the laterality is unclear.
Do not use for
Do not use it for nonspecific ankle pain, osteoarthritis, or other inflammatory arthritides without documentation of Reiter’s disease. If the record supports a different joint, a bilateral code, or a more specific site, code that instead.
Coding tip
Verify both the diagnosis wording and the joint site; unspecified codes are appropriate only when laterality is not documented.