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
Short Description
Viral infection of unspecified site
Same as the full description in the CMS dataset.
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

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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

What is the ICD-10 code for viral infection of unspecified site?

B34 is the ICD-10-CM category for viral infection of unspecified site, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

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.