ICD-10 Code M01.X6 – Direct infection of knee in infectious and parasitic diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M01.X6 – Direct infection of knee in infectious and parasitic diseases classified elsewhere
What it is
M01.X6 identifies direct infection of the knee joint caused by an infectious or parasitic disease classified elsewhere. Use it when the knee involvement is a manifestation of another documented infection.
Clinical signs
Typical findings include a painful, swollen, warm knee with restricted motion. Clinical features vary; refer to documentation for the underlying infectious or parasitic cause and whether the joint infection is directly attributed to it.
When to use this code
Use this code when the provider documents direct knee infection linked to an infectious or parasitic disease elsewhere in the record. It applies when the knee is named as the infected site and the causal disease is documented separately. You should also code the underlying infection.
Do not use for
Do not use it for nonspecific knee pain, trauma, or degenerative joint disease. It is also not for infections without documentation that the knee is directly involved or attributable to another infectious or parasitic condition.
Coding tip
Verify both the knee site and the underlying infectious or parasitic diagnosis before assigning M01.X6.