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ICD-10 Code B27.0: Gammaherpesviral mononucleosis

B27.0 is an ICD-10 diagnosis entry used to group records related to Gammaherpesviral mononucleosis. You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen. ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Certain infectious and parasitic diseases (A00-B99).

What is this code?

ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Certain infectious and parasitic diseases (A00-B99).

đź“‹Clinical overview

This ICD-10 code is commonly used when documentation describes infectious mononucleosis. The most accurate code depends on whether the record identifies gammaherpesviral, cytomegaloviral, other, or unspecified mononucleosis and whether complications such as polyneuropathy, meningitis, or another documented complication are present.

When is it used?

  • May be used when a clinician documents gammaherpesviral mononucleosis in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
  • This entry may represent a broader category rather than the most specific billable code.

đź©şClinical context

When commonly used
  • Primary-care, urgent-care, student-health, infectious-disease, emergency, and follow-up documentation where mono-like illness, fatigue, lymphadenopathy, pharyngitis, or viral testing is part of the active assessment.
  • Coding workflows where the chart identifies the viral cause or a documented complication pattern that changes final mononucleosis code specificity.
Common management context
  • Evaluation often includes symptom review, exam for lymph-node, liver, or spleen involvement, blood-count or liver-test review, activity restriction counseling, and follow-up planning for prolonged fatigue or complications.
  • Documentation usually becomes more specific when the chart identifies EBV or CMV context, or names a neurologic or other complication rather than uncomplicated mononucleosis.
  • Specialist context already linked on this page includes Infectious Disease Specialist, General Physician.

🔍Key distinctions

Important notes
  • This ICD-10 family captures infectious mononucleosis across viral-cause and complication patterns rather than a single organism-specific presentation alone.
  • Cause detail, such as gammaherpesviral versus cytomegaloviral versus other or unspecified mononucleosis, and complication detail, such as polyneuropathy or meningitis, drive final code specificity inside this family.
  • Gammaherpesviral mononucleosis is coded separately from cytomegaloviral, other, and unspecified infectious mononucleosis patterns.
  • Documentation that describes infectious mononucleosis is coded differently depending on the documented viral cause and whether neurologic or other complications are present.
Related codes to consider
B27.00Gammaherpesviral mononucleosis without complication
Related infectious-mononucleosis ICD-10 code; documentation often becomes more specific when the chart identifies gammaherpesviral versus cytomegaloviral versus other or unspecified mono, or names polyneuropathy, meningitis, or another complication.
B27.01Gammaherpesviral mononucleosis with polyneuropathy
Related infectious-mononucleosis ICD-10 code; documentation often becomes more specific when the chart identifies gammaherpesviral versus cytomegaloviral versus other or unspecified mono, or names polyneuropathy, meningitis, or another complication.
B27.02Gammaherpesviral mononucleosis with meningitis
Related infectious-mononucleosis ICD-10 code; documentation often becomes more specific when the chart identifies gammaherpesviral versus cytomegaloviral versus other or unspecified mono, or names polyneuropathy, meningitis, or another complication.
B27.09Gammaherpesviral mononucleosis with other complications
Related infectious-mononucleosis ICD-10 code; documentation often becomes more specific when the chart identifies gammaherpesviral versus cytomegaloviral versus other or unspecified mono, or names polyneuropathy, meningitis, or another complication.

Code hierarchy

chapter
1Certain infectious and parasitic diseases (A00-B99)
block
B25-B34Other viral diseases
category
B27Infectious mononucleosis
currentB27

Official coding notes

Inclusion terms
  • Mononucleosis due to Epstein-Barr virus

Where you may see this code

You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.

Related specialists

Infectious Disease SpecialistGeneral Physician

Coding guidelines

Compatibility

Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
B27.0
Replacement codes
B27.00 — Gammaherpesviral mononucleosis without complicationB27.01 — Gammaherpesviral mononucleosis with polyneuropathyB27.02 — Gammaherpesviral mononucleosis with meningitisB27.09 — Gammaherpesviral mononucleosis with other complications

Common synonyms

Gammaherpesviral mononucleosis

Frequently asked questions

Code details

CodeB27.0
SystemICD10
Display nameGammaherpesviral mononucleosis
ChapterCertain infectious and parasitic diseases (A00-B99)
BlockOther viral diseases

Flags

BillableNo
Valid clinical useNo

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.