ICD-10-CM 2027
ICD-10 code for Distomiasis
From the official ICD-10-CM alphabetic index entry “Distomiasis”. Page updated September 29, 2026.
About coding Distomiasis
The ICD-10-CM code for Distomiasis is B66.9 (Fluke infection, unspecified). The official index lists 9 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on B66.9.
Within B66, choose B66.9 (Fluke infection, unspecified) only when documentation doesn't support a more specific option: Opisthorchiasis (B66.0), Clonorchiasis (B66.1), Dicroceliasis (B66.2), Fascioliasis (B66.3), Paragonimiasis (B66.4), Fasciolopsiasis (B66.5) and other specified fluke infections (B66.8).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 867 (Other Infectious and Parasitic Diseases Diagnoses with MCC, relative weight 2.1859), DRG 868 (Other Infectious and Parasitic Diseases Diagnoses with CC, relative weight 1.0235) and DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC, relative weight 0.6787), in MDC 18 (Infectious and Parasitic Diseases, Systemic or Unspecified Sites), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific Distomiasis codes (official index)
- bile passages B66.3 — Fascioliasis
- hemic B65.9 — Schistosomiasis, unspecified
- hepatic B66.3 — Fascioliasis
- due to Clonorchis sinensis B66.1 — Clonorchiasis
- intestinal B66.5 — Fasciolopsiasis
- liver B66.3 — Fascioliasis
- due to Clonorchis sinensis B66.1 — Clonorchiasis
- lung B66.4 — Paragonimiasis
- pulmonary B66.4 — Paragonimiasis
Common questions about Distomiasis ICD-10 codes
What is the ICD-10 code for Distomiasis?
- B66.9 — Fluke infection, unspecified. More specific codes apply when the documentation supports them: B66.3, B65.9, B66.3, B66.1 and others below.
What is the ICD-10 code for bile passages distomiasis?
- B66.3 — Fascioliasis.
What is the ICD-10 code for hemic distomiasis?
- B65.9 — Schistosomiasis, unspecified.
What is the ICD-10 code for hepatic distomiasis?
- B66.3 — Fascioliasis.
What is the ICD-10 code for intestinal distomiasis?
- B66.5 — Fasciolopsiasis.
What is the ICD-10 code for liver distomiasis?
- B66.3 — Fascioliasis.
What is the ICD-10 code for lung distomiasis?
- B66.4 — Paragonimiasis.
Is B66.9 billable?
- Yes. B66.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can B66.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict B66.9 as a principal diagnosis.
Is B66.9 a CC or MCC?
- No. B66.9 is neither a CC nor an MCC under MS-DRG v44.0.