2026 ICD-10-CM Diagnosis Code B34.1Enterovirus infection, unspecified

ICD-10-CM Codes›A00–B99›B25-B34›B34

ICD-10-CM B34.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B34.1 is a billable ICD-10-CM diagnosis code for enterovirus infection, unspecified. 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 congenital coxsackie infection. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Viral infection.

Code Identity

ICD-10-CM Code
B34.1
Billable Status
Yes — Valid for Submission
Code Describes
Enterovirus infection, unspecified
Short Description
Enterovirus infection, unspecified
Same as the full description in the CMS dataset.
Parent Code
B34
Viral infection of unspecified site

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB25-B34Other viral diseases
CategoryB34Viral infection of unspecified site
This CodeB34.1Enterovirus infection, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Congenital coxsackie infection
  • Congenital infection caused by enterovirus
  • Coxsackie virus disease
  • Disease caused by Enterovirus
  • Echovirus disease
  • Enterovirus 71 infection
  • Human coxsackievirus or human echovirus
  • Human echovirus infection
  • Human enterovirus present
  • Neonatal coxsackie virus syndrome

Tabular List NotesGuidance

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

Inclusion Terms

  • Coxsackievirus infection NOS
  • Echovirus infection 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.

    • Coxsackie(virus) (infection)
    • Disease, diseased
      • coxsackie (virus) NEC
    • Disease, diseased
      • echovirus NEC
    • Disease, diseased
      • enteroviral, enterovirus NEC
    • Disease, diseased
      • nonarthropod-borne NOS (viral)
        • enterovirus NEC
    • Infection, infected, infective(opportunistic)
      • echovirus
        • unspecified nature or site
    • Infection, infected, infective(opportunistic)
      • enterovirus
    • Infection, infected, infective(opportunistic)
      • virus, viral NOS
        • coxsackie
    • Infection, infected, infective(opportunistic)
      • virus, viral NOS
        • ECHO
          • unspecified nature or site

Clinical ClassificationClinical

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

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

Patient EducationClinical

Viral Infections

Viruses are very tiny germs. They are made of genetic material (either DNA or RNA) inside of a protein coating. There are a huge number of viruses on earth. Only a small number of them can infect humans. Those viruses can infect our cells, which may cause disease.

The full article covers:

  • What are viruses?
  • How are viruses spread?
  • How do viruses cause disease?
  • What are the treatments for viral infections?
  • Can viral infections be prevented?

Read the full article at MedlinePlus

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

Convert B34.1 to ICD-9-CMHistory

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

ICD-9-CM
074.8 Coxsackie virus NEC
Approximate The match is approximate rather than exact.
ICD-9-CM
079.89 Oth specf viral infectn
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 B34.1Overview

Is B34.1 (Viral infection of unspecified site) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report enterovirus infection, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does B34.1 group to?

When enterovirus infection, unspecified 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 B34.1?

Under the General Equivalence Mappings, enterovirus infection, unspecified converts to ICD-9-CM 074.8 (coxsackie virus NEC) and 079.89 (oth specf viral infectn). 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.