ICD-10 Code M00.87 – Arthritis due to other bacteria, ankle and foot (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M00.87 – Arthritis due to other bacteria, ankle and foot
What it is
This code identifies a bacterial infection causing arthritis in the ankle or foot, when the organism is not one of the specifically listed bacteria. Use it for septic arthritis documented in these joints due to other bacteria.
Clinical signs
Typical findings include a painful, swollen, warm joint with limited motion and tenderness. Clinical features vary; refer to documentation, and confirm that the provider links the ankle or foot arthritis to bacterial infection.
When to use this code
Use M00.87 when the record clearly states arthritis of the ankle or foot due to bacteria other than the named organisms in other M00 codes. It may be supported by operative, culture, or provider documentation naming a bacterial cause. If the documentation only says “septic arthritis” without the site or organism detail, check documentation.
Do not use for
Do not use this code for noninfectious arthritis, gout, or unspecified joint pain. Also avoid it when the infection involves a different joint or when the organism is one of the specifically coded bacteria.
Coding tip
Verify both the anatomic site and the bacterial cause in the note before assigning M00.87.