ICD-10 Code M01 – Direct infections of joint in infectious and parasitic diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M01 – Direct infections of joint in infectious and parasitic diseases classified elsewhere
What it is
M01 identifies joint infections that occur as a direct manifestation of an infectious or parasitic disease classified elsewhere. Use it when the joint involvement is secondary to that underlying condition, not a standalone arthritis diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Typical findings include joint pain, swelling, warmth, reduced motion, and evidence of an associated infectious or parasitic illness affecting the joint.
When to use this code
Use M01 when the provider links the joint infection directly to an infectious or parasitic disease documented elsewhere in the record. The underlying disease should also be coded, because M01 is an etiology-related manifestation code. Check documentation if the chart does not clearly state the causal infection.
Do not use for
Do not use M01 for nonspecific joint pain, degenerative arthritis, or septic arthritis without documentation tying it to an infectious or parasitic disease classified elsewhere. If the cause is unclear, check documentation.
Coding tip
Always code the underlying infectious or parasitic disease first, then assign M01 only when the provider documents the joint infection as directly related.