ICD-10 Code B66 – Other fluke infections (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B66 – Other fluke infections
What it is
B66 identifies infections caused by flukes other than the more specifically coded species. Use it when documentation confirms a fluke infection, but the organism is not named or does not fit a more specific ICD-10 code.
Clinical signs
Clinical features vary; refer to documentation. Fluke infections may present with abdominal pain, fever, diarrhea, cough, or eosinophilia, depending on the parasite’s location and the stage of infection.
When to use this code
Use B66 when the provider documents “other fluke infection,” “fluke infestation,” or a fluke disease not classified elsewhere. It is appropriate when the species is unspecified or when the record lacks enough detail for a more specific code.
If the note identifies a particular fluke species, code that specific infection instead. Review pathology, stool studies, imaging, and infectious disease documentation to support the most accurate code selection.
Do not use for
Do not use B66 for intestinal helminth infections that are not flukes, or for a specifically named fluke with its own ICD-10 code. Check documentation.
Coding tip
Query for the organism name whenever the record only says “parasite” or “worm,” because B66 is for documented fluke infection only.