Is ICD-10-CM code A23 billable?

No, A23 (Brucellosis) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code A23 belong to?

A23 belongs to Chapter 1 of the ICD-10-CM tabular list: A00–B99 (Certain Infectious and Parasitic Diseases).

A23Not billable, use a more specific code below

Brucellosis

In Certain zoonotic bacterial diseases (A20-A28), chapter 1: Certain Infectious and Parasitic Diseases

6 billable codes under A23: 2 are a CC; none map to an HCC.A CC or MCC (major CC) is a secondary diagnosis that raises the MS-DRG payment.

Instructional notes

Includes: conditions that are coded here

Malta fever
Mediterranean fever
undulant fever

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Rules for coding infections and parasitic diseases, including HIV, organism and drug resistance codes, sepsis and septic shock, MRSA, Zika, and COVID-19.

Human Immunodeficiency Virus (HIV) Infections (page 19)
Infectious agents as the cause of diseases classified to other chapters (page 22)
Infections resistant to antibiotics (page 22)
Sepsis, Severe Sepsis, and Septic Shock (page 23)
Methicillin Resistant Staphylococcus aureus (MRSA) Conditions (page 27)
Zika virus infections (page 28)
Coronavirus infections (page 28)

Read Section I.C.1 (page 19)

All codes under A23

A23 can't be used on a claim. Pick a billable code below; grey headings group them.

A23 MS-DRGs

As the principal diagnosis, all 6 billable codes under A23 group to MS-DRG 867, 868, or 869 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

Other codes that refer to A23

Notes on these codes point to A23.

M49 Code First: brucellosis (A23.-)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

Animal Diseases and Your Health

Animal diseases that people can catch are called zoonoses. Many diseases affecting humans can be traced to animals or animal products. You can get a disease directly from an animal, or indirectly, through the environment.

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.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.