ICD-10 Code M01.X69 – Direct infection of unspecified knee in infectious and parasitic diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M01.X69 – Direct infection of unspecified knee in infectious and parasitic diseases classified elsewhere
What it is
This code identifies a direct infection involving the knee joint when the infectious or parasitic disease is classified elsewhere. Use it when the knee infection is linked to another underlying condition, and the knee is not otherwise specified.
Clinical signs
Typical findings include a painful, swollen, warm knee with reduced range of motion. Clinical features vary; refer to documentation for the underlying infection and whether the knee involvement is direct.
When to use this code
Use M01.X69 when the record documents direct infection of the unspecified knee due to an infectious or parasitic disease coded elsewhere. Confirm that the provider links the knee infection to the underlying condition and does not specify the side or a different joint.
Apply this code when the knee is the infected site and the documentation supports a secondary manifestation rather than a primary joint disorder. Check documentation if the note is unclear about causation, joint laterality, or the infectious source.
Do not use for
Do not use this code for primary septic arthritis without a documented infectious disease classified elsewhere. Also avoid it when the knee laterality is specified differently or when the condition involves a different joint.
Coding tip
Always code the underlying infectious or parasitic disease first, then add M01.X69 only when the knee infection is explicitly documented as secondary.