B27

Non-billable

Infectious mononucleosis

B27 is the ICD-10-CM code for Infectious mononucleosis. It is a non-billable category code — use a more specific child code such as B27.0 for billing.

Status
Header (non-billable)
Chapter
A00-B99
Subcodes
4
Edition
FY2026

A00-B99 Certain infectious and parasitic diseases

What this means — in plain language

MedlinePlus · NIH

What is infectious mononucleosis (mono)? Infectious mononucleosis (mono) is a disease caused by viruses .The most common cause is the Epstein-Barr virus (EBV). Mono is contagious, which means it can spread from person to person. It is common among teenagers and young adults, especially college students. What causes infectious mononucleosis (mono)? Mono can be caused by many different viruses. But it is most often…

Read more about Infectious Mononucleosis at MedlinePlus ↗

Source: U.S. National Library of Medicine (MedlinePlus). Informational only — not medical advice.

Includes

  • glandular fever
  • monocytic angina
  • Pfeiffer's disease

Frequently asked questions

What is ICD-10 code B27?
B27 is the ICD-10-CM code for "Infectious mononucleosis". It falls under A00-B99 Certain infectious and parasitic diseases.
Is B27 a billable code?
No — B27 is a non-billable header code. Use a more specific child code (such as B27.0) for billing.
What are the subcodes of B27?
B27 has 4 more specific child codes, including B27.0, B27.1, B27.8.

Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.

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