ICD-10 Code A20 – Plague (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A20 – Plague
What it is
A20 identifies plague, a serious bacterial infection caused by Yersinia pestis. Use it for confirmed or documented plague infection, including the clinical form stated in the record.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include acute fever, chills, weakness, and painful swollen lymph nodes, with possible septicemic or pneumonic involvement.
When to use this code
Use A20 when the provider documents plague or confirms Yersinia pestis infection. This may include bubonic, septicemic, pneumonic, or unspecified plague when the specific form is not stated. If the record only mentions exposure, suspicion, or testing without diagnosis, check documentation before coding.
Do not use for
Do not use A20 for nonspecific febrile illness, lymphadenitis, or other bacterial infections without documented plague. If the diagnosis is ruled out or remains unconfirmed, check documentation.
Coding tip
Capture the exact plague type documented, because the chart may support a more specific code than unspecified A20.