2026 ICD-10-CM Diagnosis Code B50.8Other severe and complicated Plasmodium falciparum malaria

ICD-10-CM Codes›A00–B99›B50-B64›B50

ICD-10-CM B50.8
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B50.8 is a billable ICD-10-CM diagnosis code for other severe and complicated Plasmodium falciparum malaria. 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. Coders also document this condition as black water fever. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections.

Code Identity

ICD-10-CM Code
B50.8
Billable Status
Yes — Valid for Submission
Code Describes
Other severe and complicated Plasmodium falciparum malaria
Short Description
Other severe and complicated Plasmodium falciparum malaria
Same as the full description in the CMS dataset.
Parent Code
B50
Plasmodium falciparum malaria

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB50-B64Protozoal diseases
CategoryB50Plasmodium falciparum malaria
This CodeB50.8Other severe and complicated Plasmodium falciparum malaria

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Black water fever
  • Falciparum malaria
  • Malarial shock lung
  • Plasmodium falciparum malaria with complication

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Severe or complicated Plasmodium falciparum malaria NOS

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • bilious, hemoglobinuric
    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • blackwater
    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • hematuric, bilious
    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • hemoglobinuric (malarial) (bilious)
    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • West
        • African
    • Hematinuria
      • malarial
    • Hematuria
      • malarial
    • Hemoglobinuria
      • malarial
    • Malaria, malarial(fever)
      • with
        • blackwater fever
    • Malaria, malarial(fever)
      • with
        • blackwater fever
          • hemoglobinuric (bilious)
    • Malaria, malarial(fever)
      • with
        • hemoglobinuria
    • Malaria, malarial(fever)
      • falciparum
        • with complications NEC
    • Malaria, malarial(fever)
      • falciparum
        • severe
    • West African fever

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INF009
Parasitic, other specified and unspecified infections
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Falciparum Malaria

    malaria resulting from infection by plasmodium falciparum.

Patient EducationClinical

Malaria

Malaria is a serious disease caused by a parasite. You get it when an infected mosquito bites you. Malaria is a major cause of death worldwide, but it is almost wiped out in the United States. The disease is mostly a problem in developing countries with warm climates. If you travel to these countries, you are at risk.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert B50.8 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
084.8 Blackwater fever
Approximate The match is approximate rather than exact.
ICD-9-CM
084.9 Malaria complicated NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About B50.8Overview

Is B50.8 (Plasmodium falciparum malaria) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other severe and complicated Plasmodium falciparum malaria on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does B50.8 group to?

When other severe and complicated Plasmodium falciparum malaria 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.

What is the ICD-9 equivalent of B50.8?

Under the General Equivalence Mappings, other severe and complicated Plasmodium falciparum malaria converts to ICD-9-CM 084.8 (blackwater fever) and 084.9 (malaria complicated NEC). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.