ICD-10-CM Code B27

Infectious mononucleosis

Version 2021 Non-Billable Code

Not Valid for Submission

B27 is a "header" nonspecific and non-billable code code, consider using a code with a higher level of specificity for a diagnosis of infectious mononucleosis. The code is NOT valid for the year 2021 for the submission of HIPAA-covered transactions.

Short Description:Infectious mononucleosis
Long Description:Infectious mononucleosis

Consider the following ICD-10 codes with a higher level of specificity:

  • B27.0 - Gammaherpesviral 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 - Cytomegaloviral 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 infectious mononucleosis
  • 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 - ... unspecified
  • B27.90 - ... unspecified without complication
  • B27.91 - ... unspecified with polyneuropathy
  • B27.92 - ... unspecified with meningitis
  • B27.99 - ... unspecified with other complication

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code B27:


This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
  • glandular fever
  • monocytic angina
  • Pfeiffer's disease

Clinical Information

  • HERPESVIRUS 4 HUMAN-. the type species of lymphocryptovirus subfamily gammaherpesvirinae infecting b cells in humans. it is thought to be the causative agent of infectious mononucleosis and is strongly associated with oral hairy leukoplakia leukoplakia hairy; burkitt lymphoma; and other malignancies.
  • INFECTIOUS MONONUCLEOSIS-. a common acute infection usually caused by the epstein barr virus herpesvirus 4 human. there is an increase in mononuclear white blood cells and other atypical lymphocytes generalized lymphadenopathy splenomegaly and occasionally hepatomegaly with hepatitis.
  • FATIGUE SYNDROME CHRONIC-. a syndrome characterized by persistent or recurrent fatigue diffuse musculoskeletal pain sleep disturbances and subjective cognitive impairment of 6 months duration or longer. symptoms are not caused by ongoing exertion; are not relieved by rest; and result in a substantial reduction of previous levels of occupational educational social or personal activities. minor alterations of immune neuroendocrine and autonomic function may be associated with this syndrome. there is also considerable overlap between this condition and fibromyalgia. from semin neurol 1998;182:237 42; ann intern med 1994 dec 15;12112: 953 9

Code Classification

  • Certain infectious and parasitic diseases (A00–B99)
    • Other viral diseases (B25-B34)
      • Infectious mononucleosis (B27)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients

Infectious Mononucleosis

Also called: Glandular fever, Kissing disease, Mono, Mononucleosis

Infectious mononucleosis, or "mono", is an infection usually caused by the Epstein-Barr virus. The virus spreads through saliva, which is why it's sometimes called "kissing disease." Mono occurs most often in teens and young adults. However, you can get it at any age. Symptoms of mono include

  • Fever
  • Sore throat
  • Swollen lymph glands

Sometimes you may also have a swollen spleen. Serious problems are rare.

A blood test can show if you have mono. Most people get better in two to four weeks. However, you may feel tired for a few months afterward. Treatment focuses on helping symptoms and includes medicines for pain and fever, warm salt water gargles and plenty of rest and fluids.

  • Epstein-Barr virus test (Medical Encyclopedia)
  • Mononucleosis (Medical Encyclopedia)
  • Mononucleosis spot test (Medical Encyclopedia)

[Learn More]