Other fluke infections (B66) ICD-10-CM
The B66 code range covers other fluke infections with 9 ICD-10-CM diagnosis codes. 8 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Codes in the B66 Range 9 codes · 8 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the B66 range.
Clonorchiasis
Infection of the biliary passages with CLONORCHIS SINENSIS, also called Opisthorchis sinensis. It may lead to inflammation of the biliary tract, proliferation of biliary epithelium, progressive portal fibrosis, and sometimes bile duct carcinoma. Extension to the liver may lead to fatty changes and cirrhosis. (From Dorland, 27th ed)
Clonorchis sinensis
A species of trematode flukes of the family Opisthorchidae. Many authorities consider this genus belonging to Opisthorchis. It is common in China and other Asiatic countries. Snails and fish are the intermediate hosts.
Dicrocoeliasis
Infection with flukes of the genus Dicrocoelium.
Echinostomiasis
Infection by flukes of the genus Echinostoma.
Fascioliasis
Liver disease caused by infections with parasitic flukes of the genus FASCIOLA, such as FASCIOLA HEPATICA.
Opisthorchiasis
Infection with flukes of the genus Opisthorchis.
Paragonimiasis
Infection with TREMATODA of the genus PARAGONIMUS.
About the B66 Code Range
The ICD-10 code section B66 covers a variety of other fluke infections, which are parasitic diseases caused by different types of flukes, also known as trematodes. These codes help identify specific fluke infections such as opisthorchiasis, clonorchiasis, fascioliasis, and paragonimiasis, each caused by distinct parasite species.
This section includes codes like B66.0 for Opisthorchiasis, also known as infection by Opisthorchis species; B66.1 for Clonorchiasis, which may involve biliary cirrhosis or bile duct fibrosis; and B66.3 for Fascioliasis, commonly caused by the sheep liver fluke. Additionally, B66.4 codes for Paragonimiasis, a lung and sometimes extrapulmonary infection, while B66.5 is for Fasciolopsiasis, an intestinal fluke infection. B66.8 covers other specified fluke infections caused by a wide range of less common parasites, and B66.9 is used when the fluke infection is unspecified, including general liver fluke or trematode infections. Using these codes ensures accurate classification of parasitic fluke diseases in medical records and billing.
Questions About This Page
How many billable codes are in the B66 range?
Of the 9 codes in this range, 8 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the B66 range classify?
The range classifies other fluke infections. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
