2027 ICD-10-CM Diagnosis Code A00.9Cholera, unspecified
ICD-10-CM Codes›A00–B99›A00-A09›A00
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
A00.9 is a billable ICD-10-CM diagnosis code for cholera, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 371 through 373. 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 3 closely related codes. Coders also document this condition as cholera. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Intestinal infection.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Cholera
- Cholera - non-O1 group vibrio
- Cholera - O139 group Vibrio cholerae
- Intestinal infection caused by Vibrio cholerae non-O139
- Intestinal infection caused by Vibrio cholerae O1
- Non-O1 and non-O139 Vibrio cholerae infection
- Vibrio cholerae enteritis of intestine
- Vibrio cholerae enteritis of small intestine
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to A00.9: its own notes plus those printed at Chapter 1. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- diseases generally recognized as communicable or transmissible
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- carrier or suspected carrier of infectious disease (Z22.-)
- certain localized infections - see body system-related chapters
- infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
- infectious and parasitic diseases specific to the perinatal period (P35-P39)
- influenza and other acute respiratory infections (J00-J22)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify resistance to antimicrobial drugs (Z16.-)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name A00.9, its category, or a range that includes it.
Excludes2 2
These codes carry an Excludes2 note naming A00.9: its condition is not part of those codes, and both may be reported when the patient has both.
- Block P35-P39 Infections specific to the perinatal period
- P37 Other congenital infectious and parasitic diseases
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.
Clinical InformationClinical
Cholera
an acute diarrheal disease endemic in india and southeast asia whose causative agent is vibrio cholerae. this condition can lead to severe dehydration in a matter of hours unless quickly treated.
Patient EducationClinical
Cholera
Cholera is a bacterial infection that causes diarrhea. The cholera bacterium is usually found in water or food that has been contaminated by feces (poop). Cholera is rare in the US. You may get it if you travel to parts of the world with poor water and sewage treatment. Outbreaks can also happen after disasters.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert A00.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About A00.9Overview
What is the ICD-10 code for cholera, unspecified?
The ICD-10-CM code for cholera, unspecified is A00.9 (sometimes written as A009). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is A00.9 (Cholera) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report cholera, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does A00.9 group to?
When cholera, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 372, 371, 373, with relative weights from 0.6945 to 1.7087 depending on complications. Higher weights mean higher Medicare reimbursement.
Is A00.9 a CC or MCC?
CMS lists A00.9 as a CC (complication or comorbidity) for FY 2027. 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 3 closely related codes in its exclusion list.
What is the ICD-9 equivalent of A00.9?
Under the General Equivalence Mappings, cholera, unspecified converts to ICD-9-CM 001.9 (cholera NOS). The mapping is a direct match.
