2026 ICD-10-CM Diagnosis Code A21.1Oculoglandular tularemia

ICD-10-CM Codes›A00–B99›A20-A28›A21

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

A21.1 is a billable ICD-10-CM diagnosis code for oculoglandular tularemia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 867 through 869. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 2 closely related codes. Coders also document this condition as bacterial corneal ulcer. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Other specified eye disorders.

Code Identity

ICD-10-CM Code
A21.1
Billable Status
Yes — Valid for Submission
Code Describes
Oculoglandular tularemia
Short Description
Oculoglandular tularemia
Same as the full description in the CMS dataset.
Parent Code
A21
Tularemia

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA20-A28Certain zoonotic bacterial diseases
CategoryA21Tularemia
This CodeA21.1Oculoglandular tularemia

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bacterial corneal ulcer
  • Glandular tularemia
  • Infection caused by Francisella
  • Oculoglandular tularemia
  • Tularemia

Tabular List NotesGuidance

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

Inclusion Terms

  • Ophthalmic tularemia

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No
CCSR EYE012
Other specified eye disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

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.

Convert A21.1 to ICD-9-CMHistory

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

ICD-9-CM
021.3 Oculoglandular tularemia
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 A21.1Overview

What is the ICD-10 code for oculoglandular tularemia?

The ICD-10-CM code for oculoglandular tularemia is A21.1 (sometimes written as A211). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is A21.1 (Tularemia) a billable code?

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

What MS-DRG does A21.1 group to?

When oculoglandular tularemia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 868, 869, with relative weights from 0.7297 to 2.0932 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A21.1 a CC or MCC?

CMS lists A21.1 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 2 closely related codes in its exclusion list.

What is the ICD-9 equivalent of A21.1?

Under the General Equivalence Mappings, oculoglandular tularemia converts to ICD-9-CM 021.3 (oculoglandular tularemia). The mapping is a direct match.