ICD-10-CM 2027
ICD-10 code for Clonorchiasis
From the official ICD-10-CM alphabetic index entry “Clonorchiasis, clonorchis infection (liver)”. Page updated September 29, 2026.
About coding Clonorchiasis
The ICD-10-CM code for Clonorchiasis is B66.1 (Clonorchiasis).
Within B66 (other fluke infections), B66.1 is specifically for Clonorchiasis. Related codes cover Opisthorchiasis (B66.0), Dicroceliasis (B66.2), Fascioliasis (B66.3), Paragonimiasis (B66.4), Fasciolopsiasis (B66.5), other specified fluke infections (B66.8) and fluke infection, unspecified (B66.9).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 441 (Disorders of Liver Except Malignancy, Cirrhosis or Alcoholic Hepatitis with MCC, relative weight 1.8219), DRG 442 (Disorders of Liver Except Malignancy, Cirrhosis or Alcoholic Hepatitis with CC, relative weight 0.9602) and DRG 443 (Disorders of Liver Except Malignancy, Cirrhosis or Alcoholic Hepatitis without CC/MCC, relative weight 0.6885), in MDC 07 (Diseases and Disorders of the Hepatobiliary System and Pancreas), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about Clonorchiasis ICD-10 codes
What is the ICD-10 code for Clonorchiasis?
- B66.1 — Clonorchiasis.
Is B66.1 billable?
- Yes. B66.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can B66.1 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict B66.1 as a principal diagnosis.
Is B66.1 a CC or MCC?
- B66.1 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.