2026 ICD-10-CM Diagnosis Code B00.9Herpesviral infection, unspecified

ICD-10-CM Codes›A00–B99›B00-B09›B00

ICD-10-CM B00.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B00.9 is a billable ICD-10-CM diagnosis code for herpesviral infection, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 606 through 607, 974 through 976. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Viral infection.

Code Identity

ICD-10-CM Code
B00.9
Billable Status
Yes — Valid for Submission
Code Describes
Herpesviral infection, unspecified
Short Description
Herpesviral infection, unspecified
Same as the full description in the CMS dataset.
Parent Code
B00
Herpesviral [herpes simplex] infections

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB00-B09Viral infections characterized by skin and mucous membrane lesions
CategoryB00Herpesviral [herpes simplex] infections
This CodeB00.9Herpesviral infection, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cellular changes consistent with Herpes simplex
  • Chronic herpes simplex
  • Chronic infection caused by herpes simplex virus co-occurrent with human immunodeficiency virus infection
  • Combined Herpes simplex 1 and Herpes simplex 2 infection
  • Herpes in pregnancy
  • Herpes simplex
  • Herpes simplex infection of buttock
  • Herpes simplex infection of skin
  • Herpes simplex type 1 infection
  • Herpes simplex type 2 infection
  • Herpesvirus infection
  • Infection caused by herpes simplex virus co-occurrent with human immunodeficiency virus infection
  • Infection of skin and/or mucous membrane caused by Herpes virus
  • Nongenital herpes simplex
  • Nongenital recurrent herpes simplex
  • Otitis externa of left external auditory canal caused by human herpesvirus 3
  • Otitis externa of right external auditory canal caused by human herpesvirus 3
  • Primary herpes simplex
  • Recurrent herpes simplex
  • Recurrent herpes simplex infection of buttock
  • Recurrent skin infection

Tabular List NotesGuidance

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

Inclusion Terms

  • Herpes simplex 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.

    • Herpes, herpesvirus, herpetic
    • Herpes, herpesvirus, herpetic
      • human
    • Herpes, herpesvirus, herpetic
      • simplex

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

  • Encephalitis, Herpes Simplex

    an acute (or rarely chronic) inflammatory process of the brain caused by simplexvirus infections which may be fatal. the majority of infections are caused by human herpesvirus 1 (herpesvirus 1, human) and less often by human herpesvirus 2 (herpesvirus 2, human). clinical manifestations include fever; headache; seizures; hallucinations; behavioral alterations; aphasia; hemiparesis; and coma. pathologically, the condition is marked by a hemorrhagic necrosis involving the medial and inferior temporal lobe and orbital regions of the frontal lobe. (from adams et al., principles of neurology, 6th ed, pp751-4)

  • Herpes Genitalis

    infection of the genitals (genitalia) with herpes simplex virus in either the males or the females.

  • Herpes Labialis

    herpes simplex, caused by type 1 virus, primarily spread by oral secretions and usually occurring as a concomitant of fever. it may also develop in the absence of fever or prior illness. it commonly involves the facial region, especially the lips and the nares. (dorland, 27th ed.)

  • Herpes Simplex

    a group of acute infections caused by herpes simplex virus type 1 or type 2 that is characterized by the development of one or more small fluid-filled vesicles with a raised erythematous base on the skin or mucous membrane. it occurs as a primary infection or recurs due to a reactivation of a latent infection. (dorland, 27th ed.)

  • Herpes Simplex Virus Protein Vmw65

    trans-acting protein that combines with host factors to induce immediate early gene transcription in herpes simplex virus.

  • Herpes Simplex Virus Vaccines

    vaccines or candidate vaccines used to prevent infection with viruses from the genus simplexvirus. this includes vaccines for hsv-1 and hsv-2.

  • Herpesvirus 1, Human

    the type species of simplexvirus causing most forms of non-genital herpes simplex in humans. primary infection occurs mainly in infants and young children and then the virus becomes latent in the dorsal root ganglion. it then is periodically reactivated throughout life causing mostly benign conditions.

  • Herpesvirus 2, Human

    a species of simplexvirus associated with genital infections (herpes genitalis). it is transmitted by sexual intercourse and close personal contact.

  • Keratitis, Herpetic

    a superficial, epithelial herpesvirus hominis infection of the cornea, characterized by the presence of small vesicles which may break down and coalesce to form dendritic ulcers (keratitis, dendritic). (dictionary of visual science, 3d ed)

  • Simplexvirus

    a genus of the family herpesviridae, subfamily alphaherpesvirinae, consisting of herpes simplex-like viruses. the type species is herpesvirus 1, human.

  • Stomatitis, Herpetic

    stomatitis caused by herpesvirus hominis. it usually occurs as acute herpetic stomatitis (or gingivostomatitis), an oral manifestation of primary herpes simplex seen primarily in children and adolescents.

  • Herpesvirus Infection

    an infection caused by a herpesvirus.

Patient EducationClinical

Herpes Simplex

Herpes is an infection that is caused by a herpes simplex virus (HSV). Oral herpes causes cold sores around the mouth or face. Genital herpes affects the genitals, buttocks or anal area. Genital herpes is a sexually transmitted infection (STI). It affects the genitals, buttocks or anal area.

Read the full article at MedlinePlus

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

Convert B00.9 to ICD-9-CMHistory

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

ICD-9-CM
054.8 H simplex complicat NOS
Approximate The match is approximate rather than exact.
ICD-9-CM
054.9 Herpes simplex NOS
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 B00.9Overview

Is B00.9 (Herpesviral [herpes simplex] infections) a billable code?

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

What MS-DRG does B00.9 group to?

When herpesviral infection, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, 974, 975, 976, with relative weights from 0.8945 to 2.8860 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of B00.9?

Under the General Equivalence Mappings, herpesviral infection, unspecified converts to ICD-9-CM 054.8 (h simplex complicat NOS) and 054.9 (herpes simplex NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.