Plague (A20) ICD-10-CM
The A20 code range covers plague with 8 ICD-10-CM diagnosis codes. 7 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- infection due to Yersinia pestis
Codes in the A20 Range 8 codes · 7 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the A20 range.
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.
Alphainfluenzavirus
A genus in the family ORTHOMYXOVIRIDAE causing influenza and other diseases in humans and animals. It contains many strains as well as antigenic subtypes of the integral membrane proteins hemagglutinin (VIRAL HEMAGGLUTININS) and NEURAMINIDASE. The type species is INFLUENZA A VIRUS.
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 A virus
The type species of the genus ALPHAINFLUENZAVIRUS 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.
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.
Morbillivirus
A genus of the family PARAMYXOVIRIDAE (subfamily PARAMYXOVIRINAE) where the virions of most members have hemagglutinin but not neuraminidase activity. All members produce both cytoplasmic and intranuclear inclusion bodies. MEASLES VIRUS is the type species.
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.
Yersinia pestis
The etiologic agent of PLAGUE in man, rats, ground squirrels, and other rodents.
About the A20 Code Range
The ICD-10 code for plague (A20) includes various specific forms of this serious bacterial infection, each with distinct symptoms and clinical presentations. These codes help accurately document cases of plague, including its bubonic, pneumonic, septicemic, and other less common types.
This group of codes covers different manifestations of plague caused by bacterial infection. For example, A20.0 is used for bubonic plague, often called simply "bubonic plague" or "plague," known for swollen lymph nodes. A20.1 refers to cellulocutaneous plague, sometimes called "cutaneous plague," which involves skin infections. A20.2 is assigned for pneumonic plague, the form affecting the lungs and known under names like "primary pneumonic plague" and "secondary pneumonic plague." Plague meningitis, septicemic plague, and other forms have their own codes (A20.3, A20.7, and A20.8) to classify cases precisely. Finally, A20.9 covers unspecified cases of plague when details are not defined. These distinctions enable medical coders to select the appropriate ICD-10 code for various plague-related diagnoses, supporting accurate tracking and treatment documentation.
Questions About This Page
How many billable codes are in the A20 range?
Of the 8 codes in this range, 7 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the A20 range classify?
The range classifies plague. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
