2026 ICD-10-CM Diagnosis Code A07.1Giardiasis [lambliasis]

ICD-10-CM Codes›A00–B99›A00-A09›A07

ICD-10-CM A07.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A07.1 is a billable ICD-10-CM diagnosis code for giardiasis [lambliasis]. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 371 through 373. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Intestinal infection; and Parasitic, other specified and unspecified infections.

Code Identity

ICD-10-CM Code
A07.1
Billable Status
Yes — Valid for Submission
Code Describes
Giardiasis [lambliasis]
Short Description
Giardiasis [lambliasis]
Same as the full description in the CMS dataset.
Parent Code
A07
Other protozoal intestinal diseases

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA00-A09Intestinal infectious diseases
CategoryA07Other protozoal intestinal diseases
This CodeA07.1Giardiasis [lambliasis]

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Colitis caused by protozoan
  • Disease caused by Hexamitidae
  • Giardia lamblia colitis
  • Giardia lamblia duodenitis
  • Giardia lamblia enteritis of intestine
  • Giardia lamblia enteritis of small intestine
  • Giardiasis
  • Infection by Giardia lamblia
  • Parasitic infection causing colitis
  • Parasitic infection causing inflammation of small intestine
  • Protozoal enteritis of small intestine

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.

    • Colitis(acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)
      • giardial
    • Diarrhea, diarrheal(disease) (infantile) (inflammatory)
      • Giardia lamblia
    • Diarrhea, diarrheal(disease) (infantile) (inflammatory)
      • giardial
    • Dysentery, dysenteric(catarrhal) (diarrhea) (epidemic) (hemorrhagic) (infectious) (sporadic) (tropical)
      • Giardia lamblia
    • Dysentery, dysenteric(catarrhal) (diarrhea) (epidemic) (hemorrhagic) (infectious) (sporadic) (tropical)
      • Lamblia
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • giardial
    • Giardiasis
    • Infection, infected, infective(opportunistic)
      • Giardia lamblia
    • Infestation
      • Giardia lamblia
    • Lambliasis, lambliosis

Clinical ClassificationClinical

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

CCSR DIG001
Intestinal infection
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR INF009
Parasitic, other specified and unspecified infections
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Giardiasis

    an infection of the small intestine caused by the flagellated protozoan giardia. it is spread via contaminated food and water and by direct person-to-person contact.

Patient EducationClinical

Giardia Infections

Giardiasis is an illness caused by a parasite called Giardia intestinalis. It lives in soil, food, and water. It may also be on surfaces that have been contaminated with waste. You can become infected if you swallow the parasite. You can also get it if you're exposed to human feces (poop) through sexual contact.

Read the full article at MedlinePlus

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

Convert A07.1 to ICD-9-CMHistory

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

ICD-9-CM
007.1 Giardiasis
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 A07.1Overview

Is A07.1 (Other protozoal intestinal diseases) a billable code?

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

What MS-DRG does A07.1 group to?

When giardiasis [lambliasis] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 371, 372, 373, with relative weights from 0.7274 to 1.7731 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A07.1?

Under the General Equivalence Mappings, giardiasis [lambliasis] converts to ICD-9-CM 007.1 (giardiasis). 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.