2026 ICD-10-CM Diagnosis Code A22.0Cutaneous anthrax

ICD-10-CM Codes›A00–B99›A20-A28›A22

ICD-10-CM A22.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A22.0 is a billable ICD-10-CM diagnosis code for cutaneous anthrax. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 606 through 607. Coders also document this condition as anthrax. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Skin and subcutaneous tissue infections.

Code Identity

ICD-10-CM Code
A22.0
Billable Status
Yes — Valid for Submission
Code Describes
Cutaneous anthrax
Short Description
Cutaneous anthrax
Same as the full description in the CMS dataset.
Parent Code
A22
Anthrax

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA20-A28Certain zoonotic bacterial diseases
CategoryA22Anthrax
This CodeA22.0Cutaneous anthrax

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Anthrax
  • Bacterial infection caused by Bacillus
  • Crust on skin
  • Cutaneous anthrax
  • Skin eschar

Tabular List NotesGuidance

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

Inclusion Terms

  • Malignant carbuncle
  • Malignant pustule

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Anthrax
      • cutaneous
    • Carbuncle
      • malignant
    • Furuncle
      • malignant
    • Pustule(nonmalignant)
      • malignant

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No
CCSR SKN001
Skin and subcutaneous tissue infections
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Anthrax

    an acute infection caused by the spore-forming bacteria bacillus anthracis. it commonly affects hoofed animals such as sheep and goats. infection in humans often involves the skin (cutaneous anthrax), the lungs (inhalation anthrax), or the gastrointestinal tract. anthrax is not contagious and can be treated with antibiotics.

  • Anthrax Vaccines

    vaccines or candidate vaccines used to prevent anthrax.

  • Bacillus anthracis

    a species of bacteria that causes anthrax in humans and animals.

  • Anthrax

    an infection caused by bacillus anthracis bacteria. it may affect the lungs, gastrointestinal tract, or skin. patients with lung infection present with fever, headaches, cough, chest pain and shortness of breath. patients with gastrointestinal infection present with nausea, vomiting and bloody diarrhea. patients with skin infection develop blisters and ulcers.

  • Anthrax Toxin Receptor 1|ANTXR1|Tumor Endothelial Marker 8

    anthrax toxin receptor 1 (564 aa, ~63 kda) is encoded by the human antxr1 gene. this protein plays a role in the regulation of both cell adhesion and cellular motility.

  • ANTXR1 Gene|ANTXR1|ANTXR1|Anthrax Toxin Receptor 1 Gene

    this gene plays a role in cell-matrix adhesion.

  • ANTXR1 wt Allele|ATR|Anthrax Toxin Receptor 1 wt Allele|FLJ10601|FLJ21776|TEM8

    human antxr1 wild-type allele is located in the vicinity of 2p13.1 and is approximately 236 kb in length. this allele, which encodes anthrax toxin receptor 1 protein, is involved in the modulation of cytoskeletal rearrangement, cellular adhesion and cell migration. mutation of the gene is associated with hemangioma capillary infantile.

  • Skin Eschar

    a crust that covers necrotic tissue in the skin that is caused by a burn or gangrene.

Patient EducationClinical

Anthrax

Anthrax is a disease caused by Bacillus anthracis, a germ that lives in soil. Many people know about it from the 2001 bioterror attacks. In the attacks, someone purposely spread anthrax through the U.S. mail. This killed five people and made 22 sick.

Read the full article at MedlinePlus

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

Convert A22.0 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
022.0 Cutaneous anthrax
Exact Match The mapping is direct, with no qualifiers.

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 A22.0Overview

Is A22.0 (Anthrax) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report cutaneous anthrax on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does A22.0 group to?

When cutaneous anthrax is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A22.0?

Under the General Equivalence Mappings, cutaneous anthrax converts to ICD-9-CM 022.0 (cutaneous anthrax). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.