ICD-10 Code M01.X – Direct infection of joint in infectious and parasitic diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M01.X – Direct infection of joint in infectious and parasitic diseases classified elsewhere
What it is
This code identifies joint infection that occurs as part of an infectious or parasitic disease classified elsewhere. Use it when the joint involvement is directly tied to the underlying condition, not coded as a primary joint disorder.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include joint pain, swelling, warmth, reduced range of motion, and evidence of an associated infectious or parasitic illness.
When to use this code
Use M01.X when the record clearly states that a joint infection is caused by an infectious or parasitic disease and the underlying disease is coded separately. This code supports cases where the joint problem is secondary to the documented infection. Check documentation if the source, organism, or joint involvement is unclear.
Do not use for
Do not use this code for primary septic arthritis without an “elsewhere classified” cause. Also avoid it when the chart does not link the joint infection to an infectious or parasitic disease.
Coding tip
Always code the underlying infectious or parasitic disease first, and use M01.X only when the provider documents a direct joint infection relationship.