ICD-10 Code for Actinomycosis
The ICD-10-CM code for actinomycosis is A42.9 — Actinomycosis, unspecified. This is the code the Alphabetic Index gives for actinomycosis with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
A42.9 is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.
Which actinomycosis code should you use?
The Alphabetic Index lists 6 codes under Actinomycosis, actinomycotic. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
| with pneumonia | A42.0 | Pulmonary actinomycosis | |
| abdominal | A42.1 | Abdominal actinomycosis | |
| cervicofacial | A42.2 | Cervicofacial actinomycosis | |
| cutaneous | A42.89 | Other forms of actinomycosis | |
| gastrointestinal | A42.1 | Abdominal actinomycosis | |
| pulmonary | A42.0 | Pulmonary actinomycosis | |
| sepsis | A42.7 | Actinomycotic sepsis | |
| specified site NEC | A42.89 | Other forms of actinomycosis |
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources