2027 ICD-10-CM Diagnosis Code A79Other rickettsioses

ICD-10-CM Codes›A00–B99›A75-A79›A79

ICD-10-CM A79
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A79 is a non-billable ICD-10-CM category code for other rickettsioses, so it cannot be submitted on claims. Use a more specific code from this category instead, such as A79.0, A79.1, A79.81, and A79.82.

Code Identity

ICD-10-CM Code
A79
Billable Status
No — Non-Billable Category
Code Describes
Other rickettsioses
Short Description
Other rickettsioses
Same as the full description in the CMS dataset.
Chapter
A75-A79
Rickettsioses

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA75-A79Rickettsioses
CategoryA79Other rickettsioses
This CodeA79Other rickettsioses

Specific Coding for Other rickettsiosesOverview

Non-specific codes like A79 require more characters. Use one of these billable codes instead:

  • Use A79.0 for Trench fever

  • Use A79.1 for Rickettsialpox due to Rickettsia akari

  • A79.8 for Other specified rickettsioses

  • Use A79.81 for Rickettsiosis due to Ehrlichia sennetsu

  • Use A79.82 for Anaplasmosis [A. phagocytophilum]

  • Use A79.89 for Other specified rickettsioses

  • Use A79.9 for Rickettsiosis, unspecified

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A79: 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.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • 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.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • 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.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • code to identify resistance to antimicrobial drugs (Z16.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

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.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About A79Overview

What is the ICD-10 code for other rickettsioses?

A79 is the ICD-10-CM category for other rickettsioses, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is A79 (Other rickettsioses) a billable code?

No. This is a category header that groups the codes for other rickettsioses, and headers cannot be submitted on claims. Claims for other rickettsioses need a more specific code from this category, such as A79.0, A79.1, and A79.81.