2023 ICD-10-CM Diagnosis Code B27

Infectious mononucleosis

    2016 2017 2018 2019 2020 2021 2022 2023 Non-Billable/Non-Specific Code
  • B27 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail.
  • The 2023 edition of ICD-10-CM B27 became effective on October 1, 2022.
  • This is the American ICD-10-CM version of B27 - other international versions of ICD-10 B27 may differ.
Includes Help
"Includes" further defines, or give examples of, the content of the code or category.
  • glandular fever
  • monocytic angina
  • Pfeiffer's disease
The following code(s) above B27 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to B27:
  • A00-B99
    2023 ICD-10-CM Range A00-B99

    Certain infectious and parasitic diseases

    • diseases generally recognized as communicable or transmissible
    Type 1 Excludes
    • certain localized infections - see body system-related chapters
    Type 2 Excludes
    • carrier or suspected carrier of infectious disease (Z22.-)
    • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
    • infectious and parasitic diseases specific to the perinatal period (P35-P39)
    • influenza and other acute respiratory infections (J00-J22)
    Use Additional
    • code to identify resistance to antimicrobial drugs (Z16.-)
    Certain infectious and parasitic diseases
Clinical Information
  • 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.
  • Acute disease characterized by fever and swollen lymph nodes and an abnormal increase of mononuclear leucocytes or monocytes in the bloodstream; not highly contagious; some believe it can be transmitted by kissing.
  • Infectious mononucleosis, or "mono", is an infection 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 15 to 17-year-olds. 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.
Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
  • 2020 (effective 10/1/2019): No change
  • 2021 (effective 10/1/2020): No change
  • 2022 (effective 10/1/2021): No change
  • 2023 (effective 10/1/2022): No change
Code annotations containing back-references to B27:
  • Type 1 Excludes: G02
    , D72.821
    , J02.8
    ICD-10-CM Diagnosis Code G02

    Meningitis in other infectious and parasitic diseases classified elsewhere

      2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code Manifestation Code
    Code First
    • underlying disease, such as:
    • African trypanosomiasis (B56.-)
    • poliovirus infection (A80.-)
    Type 1 Excludes
    • candidal meningitis (B37.5)
    • coccidioidomycosis meningitis (B38.4)
    • cryptococcal meningitis (B45.1)
    • herpesviral [herpes simplex] meningitis (B00.3)
    • infectious mononucleosis complicated by meningitis (B27.- with fifth character 2)
    • measles complicated by meningitis (B05.1)
    • meningoencephalitis and meningomyelitis in other infectious and parasitic diseases classified elsewhere (G05)
    • mumps meningitis (B26.1)
    • rubella meningitis (B06.02)
    • varicella [chickenpox] meningitis (B01.0)
    • zoster meningitis (B02.1)
    ICD-10-CM Diagnosis Code D72.821

    Monocytosis (symptomatic)

      2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
    Type 1 Excludes
    • infectious mononucleosis (B27.-)
    ICD-10-CM Diagnosis Code J02.8

    Acute pharyngitis due to other specified organisms

      2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
    Type 1 Excludes
    • acute pharyngitis due to coxsackie virus (B08.5)
    • acute pharyngitis due to gonococcus (A54.5)
    • acute pharyngitis due to herpes [simplex] virus (B00.2)
    • acute pharyngitis due to infectious mononucleosis (B27.-)
    • enteroviral vesicular pharyngitis (B08.5)
    Use Additional
    • code (B95-B97) to identify infectious agent
ICD-10-CM Codes Adjacent To B27
B26.2 Mumps encephalitis
B26.3 Mumps pancreatitis
B26.8 Mumps with other complications
B26.81 Mumps hepatitis
B26.82 Mumps myocarditis
B26.83 Mumps nephritis
B26.84 Mumps polyneuropathy
B26.85 Mumps arthritis
B26.89 Other mumps complications
B26.9 Mumps without complication
B27 Infectious mononucleosis
B27.0 Gammaherpesviral mononucleosis
B27.00 …… without complication
B27.01 …… with polyneuropathy
B27.02 …… with meningitis
B27.09 …… with other complications
B27.1 Cytomegaloviral mononucleosis
B27.10 …… without complications
B27.11 …… with polyneuropathy
B27.12 …… with meningitis
B27.19 …… with other complication

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.