2026 ICD-10-CM Diagnosis Code A21Tularemia

ICD-10-CM Codes›A00–B99›A20-A28›A21

ICD-10-CM A21
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A21 is a non-billable ICD-10-CM category code for tularemia, so it cannot be submitted on claims. Use a more specific code from this category instead, such as A21.0, A21.1, A21.2, and A21.3.

Code Identity

ICD-10-CM Code
A21
Billable Status
No — Non-Billable Category
Code Describes
Tularemia
Short Description
Tularemia
Same as the full description in the CMS dataset.
Chapter
A20-A28
Certain zoonotic bacterial diseases

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA20-A28Certain zoonotic bacterial diseases
CategoryA21Tularemia
This CodeA21Tularemia

Specific Coding for TularemiaOverview

Non-specific codes like A21 require more characters. Use one of these billable codes instead:

  • Use A21.0 for Ulceroglandular tularemia

  • Use A21.1 for Oculoglandular tularemia

  • Use A21.2 for Pulmonary tularemia

  • Use A21.3 for Gastrointestinal tularemia

  • Use A21.7 for Generalized tularemia

  • Use A21.8 for Other forms of tularemia

  • Use A21.9 for Tularemia, unspecified

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Includes

  • deer-fly fever
  • infection due to Francisella tularensis
  • rabbit fever

Clinical InformationClinical

  • Tularemia

    a plague-like disease of rodents, transmissible to man. it is caused by francisella tularensis and is characterized by fever, chills, headache, backache, and weakness.

  • Francisella tularensis

    the etiologic agent of tularemia in man and other warm-blooded animals.

  • Tularemia

    a serious gram-negative bacterial infection caused by francisella tularensis. it is transmitted to humans through bites from infected insects, inhaling airborne bacteria, handling infected animals, or consuming contaminated food or water. signs and symptoms include skin ulcers, mouth sores, lymphadenopathy, sore throat, fever and pneumonia.

Patient EducationClinical

Bacterial Infections

Bacteria are tiny organisms (living things) that have only one cell. Under a microscope, they look like balls, rods, or spirals. They can be found almost everywhere on Earth. There are lots of bacteria in and on your body. In fact, your body has about 10 times more bacteria cells than human cells.

The full article covers:

  • What are bacteria?
  • How do bacterial infections spread?
  • What are the treatments for bacterial infections?
  • Can bacterial infections be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About A21Overview

Is A21 (Tularemia) a billable code?

No. This is a category header that groups the codes for tularemia, and headers cannot be submitted on claims. Claims for tularemia need a more specific code from this category, such as A21.0, A21.1, and A21.2.