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v1.0.0
ICD-10 Guide
ICD-10 CodesB27

B27

Infectious mononucleosis

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/05/2025

Code Description

ICD-10 B27 is a billable code used to indicate a diagnosis of infectious mononucleosis.

Key Diagnostic Point:

Infectious mononucleosis, commonly known as mono, is primarily caused by the Epstein-Barr virus (EBV), a member of the herpes virus family. It is characterized by fever, sore throat, swollen lymph nodes, and fatigue. The virus is typically transmitted through saliva, which is why it is often referred to as the 'kissing disease.' Diagnosis is usually made based on clinical presentation and confirmed through laboratory tests, including heterophile antibody tests (such as the Monospot test) and specific EBV serologies. While most cases are self-limiting, some patients may require supportive care, and in rare instances, corticosteroids may be prescribed to manage severe symptoms. Complications can include splenic rupture, hepatitis, and airway obstruction due to lymphadenopathy. Understanding the nuances of this condition is crucial for accurate coding and appropriate patient management.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variability in clinical presentation among patients
  • Need for laboratory confirmation through specific tests
  • Potential for misdiagnosis with other viral infections
  • Documentation of complications or co-morbidities

Audit Risk Factors

  • Inadequate documentation of symptoms and clinical findings
  • Failure to document laboratory test results
  • Misclassification of the condition as a different viral infection
  • Lack of follow-up documentation for complications

Specialty Focus

Medical Specialties

Primary Care

Documentation Requirements

Detailed history of symptoms, physical examination findings, and results of diagnostic tests.

Common Clinical Scenarios

Patients presenting with fatigue, sore throat, and lymphadenopathy.

Billing Considerations

Ensure thorough documentation of symptom duration and severity to support the diagnosis.

Infectious Disease

Documentation Requirements

Comprehensive lab results, including EBV serology and any complications.

Common Clinical Scenarios

Patients with atypical presentations or severe complications requiring specialized management.

Billing Considerations

Document any differential diagnoses considered and the rationale for the final diagnosis.

Coding Guidelines

Inclusion Criteria

Use B27 When
  • According to ICD
  • 10 guidelines, B27 should be used when the diagnosis of infectious mononucleosis is confirmed through clinical and laboratory findings

Exclusion Criteria

Do NOT use B27 When
  • Exclusion criteria include other viral infections that may present similarly, such as cytomegalovirus or HIV

Related Codes

Child Codes

20 codes
B27.0
Infectious mononucleosis
B27.00
Gammaherpesviral mononucleosis without complication
B27.01
Gammaherpesviral mononucleosis with polyneuropathy
B27.02
Gammaherpesviral mononucleosis with meningitis
B27.09
Gammaherpesviral mononucleosis with other complications
B27.1
Infectious mononucleosis
B27.10
Cytomegaloviral mononucleosis without complications
B27.11
Cytomegaloviral mononucleosis with polyneuropathy
B27.12
Cytomegaloviral mononucleosis with meningitis
B27.19
Cytomegaloviral mononucleosis with other complication
B27.8
Other viral agents as the cause of diseases classified elsewhere
B27.80
Other infectious mononucleosis without complication
B27.81
Other infectious mononucleosis with polyneuropathy
B27.82
Other infectious mononucleosis with meningitis
B27.89
Other infectious mononucleosis with other complication
B27.9
Infectious mononucleosis, unspecified
B27.90
Infectious mononucleosis, unspecified without complication
B27.91
Infectious mononucleosis, unspecified with polyneuropathy
B27.92
Infectious mononucleosis, unspecified with meningitis
B27.99
Infectious mononucleosis, unspecified with other complication

Related CPT Codes

86790CPT Code

EBV antibody test

Clinical Scenario

Used to confirm the diagnosis of infectious mononucleosis.

Documentation Requirements

Document the reason for the test and the results.

Specialty Considerations

Infectious disease specialists may require additional serological tests.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of infectious mononucleosis, improving the accuracy of diagnosis and treatment tracking. The granularity of ICD-10 codes helps in better understanding the epidemiology and management of the condition.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of infectious mononucleosis, improving the accuracy of diagnosis and treatment tracking. The granularity of ICD-10 codes helps in better understanding the epidemiology and management of the condition.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of infectious mononucleosis, improving the accuracy of diagnosis and treatment tracking. The granularity of ICD-10 codes helps in better understanding the epidemiology and management of the condition.

Resources

Clinical References

  • •
    CDC - Infectious Mononucleosis

Coding & Billing References

  • •
    CDC - Infectious Mononucleosis

Frequently Asked Questions

What are the common symptoms of infectious mononucleosis?

Common symptoms include fever, sore throat, swollen lymph nodes, and extreme fatigue. Some patients may also experience headaches, rash, and liver enlargement.