2026 ICD-10-CM Diagnosis Code B33.4Hantavirus (cardio)-pulmonary syndrome [HPS] [HCPS]

ICD-10-CM CodesA00–B99B25-B34B33

ICD-10-CM B33.4
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B33.4 is a billable ICD-10-CM diagnosis code for hantavirus (cardio)-pulmonary syndrome [HPS] [HCPS]. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 865 through 866. Coders also document this condition as disease caused by Hantavirus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Viral infection.

Code Identity

ICD-10-CM Code
B33.4
Billable Status
Yes — Valid for Submission
Code Describes
Hantavirus (cardio)-pulmonary syndrome [HPS] [HCPS]
Short Description
Hantavirus (cardio)-pulmonary syndrome [HPS] [HCPS]
Same as the full description in the CMS dataset.
Parent Code
Other viral diseases, not elsewhere classified

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB25-B34Other viral diseases
CategoryB33Other viral diseases, not elsewhere classified
This CodeB33.4Hantavirus (cardio)-pulmonary syndrome [HPS] [HCPS]

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Disease caused by Hantavirus
  • Hantavirus pulmonary syndrome
  • Sin Nombre virus encephalitis

Tabular List NotesGuidance

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

Inclusion Terms

  • Hantavirus disease with pulmonary manifestations
  • Sin nombre virus disease

Use Additional Code

  • code to identify any associated acute kidney failure N17.9

Type 1 Excludes

  • hantavirus disease with renal manifestations A98.5
  • hemorrhagic fever with renal manifestations A98.5

Index to Diseases and InjuriesGuidance

External Cause of Injuries IndexGuidance

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

    • Disease, diseased
      • Hantavirus, with pulmonary manifestations
    • Disease, diseased
      • sin nombre virus
    • Disease, diseased
      • viral, virus
        • Hanta (with renal manifestations) (Dobrava) (Puumala) (Seoul)
          • with pulmonary manifestations (Andes) (Bayou) (Bermejo) (Black Creek Canal) (Choclo) (Juquitiba) (Laguna negra) (Lechiguanas) (New York) (Oran) (Sin nombre)
    • Disease, diseased
      • viral, virus
        • Sin nombre (Hantavirus) (cardio)-pulmonary syndrome)
    • Hantavirus disease(with renal manifestations) (Dobrava) (Puumala) (Seoul)
      • with pulmonary manifestations (Andes) (Bayou) (Bermejo) (Black Creek Canal) (Choclo) (Juquitiba) (Laguna negra) (Lechiguanas) (New York) (Oran) (Sin nombre)
    • Sin Nombre virus disease(Hantavirus) (cardio)-pulmonary syndrome
    • Syndrome
      • hantavirus (cardio)-pulmonary (HPS) (HCPS)

Clinical ClassificationClinical

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

CCSR INF008
Viral infection
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Hantavirus Pulmonary Syndrome

    acute respiratory illness in humans caused by the sin nombre virus whose primary rodent reservoir is the deer mouse peromyscus maniculatus. first identified in the southwestern united states, this syndrome is characterized most commonly by fever, myalgias, headache, cough, and rapid respiratory failure.
  • Sin Nombre virus

    a species of orthohantavirus which emerged in the four corners area of the united states in 1993. it causes a serious, often fatal pulmonary illness (hantavirus pulmonary syndrome) in humans. transmission is by inhaling aerosolized rodent secretions that contain virus particles, carried especially by deer mice (peromyscus maniculatus) and pinyon mice (p. truei).
  • Hantavirus Pulmonary Syndrome

    an infection caused by hantaviruses. it manifests with flu-like symptoms but it rapidly progresses to life-threatening respiratory problems.

Patient EducationClinical

Hantavirus Infections

Hantavirus pulmonary syndrome (HPS) is a rare but deadly viral infection. It is spread by mice and rats. They shed the virus in their urine, droppings, and saliva. Tiny droplets with the virus can enter the air. People can get the disease if they breathe infected air or come into contact with rodents or their urine or droppings.

Read the full article at MedlinePlus

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

Convert B33.4 to ICD-9-CMHistory

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

ICD-9-CM
079.81 Hantavirus infection
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 B33.4Overview

Is B33.4 (Other viral diseases, not elsewhere classified) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report hantavirus (cardio)-pulmonary syndrome [HPS] [HCPS] on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does B33.4 group to?

When hantavirus (cardio)-pulmonary syndrome [HPS] [HCPS] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 865, 866, with relative weights from 0.8696 to 1.4983 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of B33.4?

Under the General Equivalence Mappings, hantavirus (cardio)-pulmonary syndrome [HPS] [HCPS] converts to ICD-9-CM 079.81 (hantavirus infection). 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.