2026 ICD-10-CM Diagnosis Code B66.8Other specified fluke infections
ICD-10-CM Codes›A00–B99›B65-B83›B66
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
B66.8 is a billable ICD-10-CM diagnosis code for other specified fluke infections. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 867 through 869. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 8 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Cutaneous fluke infection
- Disease caused by Cyclocoelidae
- Disease caused by Dactylogyridae
- Disease caused by Dicrocoeliidae
- Disease caused by Diplostomatidae
- Disease caused by Echinostomatidae
- Disease caused by Gastrodiscoides
- Disease caused by Heterophyidae
- Disease caused by Notocotylidae
- Disease caused by Paramphistomatidae
- Disease caused by Plagiorchiidae
- Disease caused by Sanguinicolidae
- Disease caused by Strigeidae
- Echinostoma ilocanum infection
- Echinostomiasis
- Gastrodiscoidiasis
- Haplorchiasis
- Infection by Alaria
- Infection by Amphimerus
- Infection by Amphimerus elongatus
- Infection by Apatemon
- Infection by Apophallus
- Infection by Athesmia
- Infection by Athesmia foxi
- Infection by Austrobilharzia
- Infection by Bilharziella
- Infection by Calicophoron
- Infection by Catatropis
- Infection by Ceylonocotyle
- Infection by Collyriculum
- Infection by Collyriculum faba
- Infection by Cotylophoron
- Infection by Cotylurus
- Infection by Cryptocotyle
- Infection by Dactylogyrus
- Infection by Diplostomum
- Infection by Echinochasmus
- Infection by Echinoparyphium
- Infection by Echinostoma lindoense
- Infection by Euparyphium
- Infection by Gastrodiscoides hominis
- Infection by Gigantobilharzia
- Infection by Gigantocotyle
- Infection by Heterobilharzia
- Infection by Heterobilharzia americanum
- Infection by Heterophyes heterophyes
- Infection by Hypodereum
- Infection by Metagonimus yokogawai
- Infection by Metorchis
- Infection by Nanophyetus
- Infection by Nanophyetus salmincola
- Infection by Notocotylus
- Infection by Orientobilharzia
- Infection by Orientobilharzia harinasutai
- Infection by Ornithobilharzia
- Infection by pancreaticum
- Infection by Paramphistomum
- Infection by Plagiorchis
- Infection by Platynosomum
- Infection by Platynosomum concinnum
- Infection by Platynosomum fastosum
- Infection by Prosthogonimus
- Infection by Prosthogonimus macrorchis
- Infection by Sanguinicola
- Infection by Schistosomatium
- Infection by Stellantchasmus falcatus
- Infection by Strigea
- Infection by Trichobilharzia
- Infection by Trichobilharzia ocellata
- Infection by Trichobilharzia physellae
- Infection by Trichobilharzia stagnicolae
- Infection by Typhlocoelum
- Infection caused by Eurytrema
- Infection of intestine caused by Fibricola seoulensis
- Phaneropsuliasis
- Poikilorchiasis
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Echinostomiasis
- Heterophyiasis
- Metagonimiasis
- Nanophyetiasis
- Watsoniasis
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Echinostomiasis B66.8
Infection, infected, infective (opportunistic) B99.9
Metagonimus B66.8
Stellantchasmus falcatus B66.8
Echinostomum ilocanum B66.8
specified type NEC B66.8
Gastrodiscoides hominis B66.8
Metagonimus (yokogawai) B66.8
Stellantchasmus falcatus B66.8
Metagonimiasis B66.8
Nanophyetiasis B66.8
Watsoniasis B66.8
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Echinostomiasis
infection by flukes of the genus echinostoma.
Patient EducationClinical
Parasitic Diseases
Parasites are living things that use other living things - like your body - for food and a place to live. You can get them from contaminated food or water, a bug bite, or sexual contact. Some parasitic diseases are easily treated and some are not.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert B66.8 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About B66.8Overview
What is the ICD-10 code for other specified fluke infections?
The ICD-10-CM code for other specified fluke infections is B66.8 (sometimes written as B668). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is B66.8 (Other fluke infections) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other specified fluke infections on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does B66.8 group to?
When other specified fluke infections is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 868, 869, with relative weights from 0.7297 to 2.0932 depending on complications. Higher weights mean higher Medicare reimbursement.
Is B66.8 a CC or MCC?
CMS lists B66.8 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 8 closely related codes in its exclusion list.
What is the ICD-9 equivalent of B66.8?
Under the General Equivalence Mappings, other specified fluke infections converts to ICD-9-CM 121.5 (metagonimiasis), 121.6 (heterophyiasis), and 121.8 (trematode infection NEC). The mapping is approximate, so confirm the match fits the documentation.
