2026 ICD-10-CM Diagnosis Code B34Viral infection of unspecified site

ICD-10-CM Codes›A00–B99›B25-B34›B34

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

B34 is a non-billable ICD-10-CM category code for viral infection of unspecified site, so it cannot be submitted on claims. Use a more specific code from this category instead, such as B34.0, B34.1, B34.2, and B34.3.

Code Identity

ICD-10-CM Code
B34
Billable Status
No — Non-Billable Category
Code Describes
Viral infection of unspecified site
Chapter
B25-B34
Other viral diseases

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB25-B34Other viral diseases
CategoryB34Viral infection of unspecified site
This CodeB34Viral infection of unspecified site

Specific Coding for Viral infection of unspecified siteOverview

Non-specific codes like B34 require more characters. Use one of these billable codes instead:

  • Use B34.0 for Adenovirus infection, unspecified

  • Use B34.1 for Enterovirus infection, unspecified

  • Use B34.2 for Coronavirus infection, unspecified

  • Use B34.3 for Parvovirus infection, unspecified

  • Use B34.4 for Papovavirus infection, unspecified

  • Use B34.8 for Other viral infections of unspecified site

  • Use B34.9 for Viral infection, unspecified

Tabular List NotesGuidance

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

Type 1 Excludes

  • anogenital human papillomavirus infection A63.0
  • cytomegaloviral disease NOS B25.9
  • herpesvirus herpes simplex infection NOS B00.9
  • retrovirus infection NOS B33.3
  • viral agents as the cause of diseases classified elsewhere B97
  • viral warts due to human papillomavirus infection B07

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.

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 B34Overview

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

No. This is a category header that groups the codes for viral infection of unspecified site, and headers cannot be submitted on claims. Claims for viral infection of unspecified site need a more specific code from this category, such as B34.0, B34.1, and B34.2.