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ICD-10-CM 2027 diagnosis code

B64Unspecified protozoal disease

✓ Billable / specific

B64 is a valid, billable ICD-10-CM code for unspecified protozoal disease. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Protozoal disease.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About B64

B64 is the ICD-10-CM diagnosis code for unspecified protozoal disease. It belongs to block B50-B64 (protozoal diseases) and chapter 1 (certain infectious and parasitic diseases). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

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.

Before ICD-10, this condition was coded in ICD-9-CM as 088.9 (arthropod-borne disease, unspecified) and 136.9 (unspecified infectious and parasitic diseases).

Notes that apply from higher levels

Instructions written at a parent level also apply to B64.

Broader instructions also apply from B50-B64 Protozoal diseases and Chapter 1: Certain infectious and parasitic diseases.

Alphabetic index entries

4 entries

Terms in the official ICD-10-CM index that lead to B64.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 088.9Arthropod-borne disease, unspecifiedapproximate
  • 136.9Unspecified infectious and parasitic diseasesapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about B64

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.

What DRG does B64 group to?

B64 is used in the MS-DRG v44.0 logic for MS-DRG 867 (Other Infectious and Parasitic Diseases Diagnoses with MCC), MS-DRG 868 (Other Infectious and Parasitic Diseases Diagnoses with CC) and MS-DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for B64?

The CMS General Equivalence Mappings map B64 to ICD-9-CM 088.9 and 136.9.