ICD-10-CM Code A20.9

Plague, unspecified

Version 2021 Billable Code

Valid for Submission

A20.9 is a billable code used to specify a medical diagnosis of plague, unspecified. The code is valid for the fiscal year 2021 for the submission of HIPAA-covered transactions. The ICD-10-CM code A20.9 might also be used to specify conditions or terms like plague.

Short Description:Plague, unspecified
Long Description:Plague, unspecified

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code A20.9 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Plague

Clinical Information

  • AFRICAN HORSE SICKNESS-. an insect borne reovirus infection of horses mules and donkeys in africa and the middle east; characterized by pulmonary edema cardiac involvement and edema of the head and neck.
  • FELINE PANLEUKOPENIA-. a highly contagious dna virus infection of the cat family characterized by fever enteritis and bone marrow changes. it is also called feline ataxia feline agranulocytosis feline infectious enteritis cat fever cat plague and show fever. it is caused by feline panleukopenia virus or the closely related mink enteritis virus or canine parvovirus.
  • INFLUENZA IN BIRDS-. infection of domestic and wild fowl and other birds with influenza a virus. avian influenza usually does not sicken birds but can be highly pathogenic and fatal in domestic poultry.
  • INFLUENZA A VIRUS-. the type species of the genus influenzavirus a that causes influenza and other diseases in humans and animals. antigenic variation occurs frequently between strains allowing classification into subtypes and variants. transmission is usually by aerosol human and most non aquatic hosts or waterborne ducks. infected birds shed the virus in their saliva nasal secretions and feces.
  • PLAGUE-. an acute infectious disease caused by yersinia pestis that affects humans wild rodents and their ectoparasites. this condition persists due to its firm entrenchment in sylvatic rodent flea ecosystems throughout the world. bubonic plague is the most common form.
  • PLAGUE VACCINE-. a suspension of killed yersinia pestis used for immunizing people in enzootic plague areas.
  • RINDERPEST-. a viral disease of cloven hoofed animals caused by morbillivirus. it may be acute subacute or chronic with the major lesions characterized by inflammation and ulceration of the entire digestive tract. the disease was declared successfully eradicated worldwide in 2010.

Diagnostic Related Groups

The ICD-10 code A20.9 is grouped in the following groups for version MS-DRG V38.0 What are Diagnostic Related Groups?
The Diagnostic Related Groups (DRGs) are a patient classification scheme which provides a means of relating the type of patients a hospital treats. The DRGs divides all possible principal diagnoses into mutually exclusive principal diagnosis areas referred to as Major Diagnostic Categories (MDC).
applicable from 10/01/2020 through 09/30/2021.


Convert A20.9 to ICD-9

Code Classification

  • Certain infectious and parasitic diseases (A00–B99)
    • Certain zoonotic bacterial diseases (A20-A28)

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


Also called: Bubonic plague, Pneumonic plague

Plague is an infection caused by the bacterium Yersinia pestis. The bacteria are found mainly in rats and in the fleas that feed on them. People and other animals can get plague from rat or flea bites. In the past, plague destroyed entire civilizations. Today plague is uncommon, due to better living conditions and antibiotics.

There are three forms of plague:

  • Bubonic plague causes the tonsils, adenoids, spleen, and thymus to become inflamed. Symptoms include fever, aches, chills, and tender lymph glands.
  • In septicemic plague, bacteria multiply in the blood. It causes fever, chills, shock, and bleeding under the skin or other organs.
  • Pneumonic plague is the most serious form. Bacteria enter the lungs and cause pneumonia. People with the infection can spread this form to others. This type could be a bioterror agent.

Lab tests can diagnose plague. Treatment is a strong antibiotic. There is no vaccine.

NIH: National Institute of Allergy and Infectious Diseases

  • Plague (Medical Encyclopedia)

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