ICD-10 Code A42.89 – Other forms of actinomycosis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A42.89 – Other forms of actinomycosis
What it is
A42.89 identifies actinomycosis that does not fit a more specific site or form. It is a chronic bacterial infection caused by Actinomyces species, documented when the record supports another specified presentation.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include chronic swelling, draining sinus tracts, or abscess formation, but you should code only when the provider documents actinomycosis.
When to use this code
Use A42.89 when the provider documents actinomycosis and the case is not described by a more specific ICD-10-CM actinomycosis code. This may apply when the chart states an other or unspecified form with enough clinical support.
If the location or type is unclear, check documentation before assigning this code. Do not infer actinomycosis from a culture, imaging report, or problem list alone unless the diagnosis is confirmed by the clinician.
Do not use for
Do not use this code for a more specific actinomycosis site, such as cervicofacial, thoracic, abdominal, or pelvic disease. Do not use it when actinomycosis is only suspected or not documented.
Coding tip
Confirm that the provider’s final diagnosis says actinomycosis and that no more specific site code applies before selecting A42.89.