ICD-10-CM 2027
ICD-10 code for protozoal disease
From the official ICD-10-CM alphabetic index entry “Disease, diseased › protozoal”. Page updated September 29, 2026.
About coding protozoal disease
The ICD-10-CM code for protozoal disease is B64 (Unspecified protozoal disease). The official index lists 5 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on B64.
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.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
More specific protozoal disease codes (official index)
- acanthamebiasis
- African trypanosomiasis
- babesiosis B60.00 — Babesiosis, unspecified
- Chagas disease
- intestine, intestinal A07.9 — Protozoal intestinal disease, unspecified
- leishmaniasis
- malaria
- naegleriasis B60.2 — Naegleriasis
- pneumocystosis B59 — Pneumocystosis
- specified organism NEC B60.8 — Other specified protozoal diseases
- toxoplasmosis
Common questions about protozoal disease ICD-10 codes
What is the ICD-10 code for protozoal disease?
- B64 — Unspecified protozoal disease. More specific codes apply when the documentation supports them: B60.00, A07.9, B60.2, B59 and others below.
What is the ICD-10 code for babesiosis protozoal disease?
- B60.00 — Babesiosis, unspecified.
What is the ICD-10 code for naegleriasis protozoal disease?
- B60.2 — Naegleriasis.
What is the ICD-10 code for pneumocystosis protozoal disease?
- B59 — Pneumocystosis.
Is B64 billable?
- Yes. B64 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can B64 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict B64 as a principal diagnosis.
Is B64 a CC or MCC?
- No. B64 is neither a CC nor an MCC under MS-DRG v44.0.