2026 ICD-10-CM Diagnosis Code A77Spotted fever [tick-borne rickettsioses]

ICD-10-CM Codes›A00–B99›A75-A79›A77

ICD-10-CM A77
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A77 is a non-billable ICD-10-CM category code for spotted fever [tick-borne rickettsioses], so it cannot be submitted on claims. Use a more specific code from this category instead, such as A77.0, A77.1, A77.2, and A77.3.

Code Identity

ICD-10-CM Code
A77
Billable Status
No — Non-Billable Category
Code Describes
Spotted fever [tick-borne rickettsioses]
Chapter
A75-A79
Rickettsioses

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA75-A79Rickettsioses
CategoryA77Spotted fever [tick-borne rickettsioses]
This CodeA77Spotted fever [tick-borne rickettsioses]

Specific Coding for Spotted fever [tick-borne rickettsioses]Overview

Non-specific codes like A77 require more characters. Use one of these billable codes instead:

  • Use A77.0 for Spotted fever due to Rickettsia rickettsii

  • Use A77.1 for Spotted fever due to Rickettsia conorii

  • Use A77.2 for Spotted fever due to Rickettsia siberica

  • Use A77.3 for Spotted fever due to Rickettsia australis

  • A77.4 for Ehrlichiosis

  • Use A77.40 for Ehrlichiosis, unspecified

  • Use A77.41 for Ehrlichiosis chaffeensis [E. chaffeensis]

  • Use A77.49 for Other ehrlichiosis

  • Use A77.8 for Other spotted fevers

  • Use A77.9 for Spotted fever, unspecified

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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About A77Overview

Is A77 (Spotted fever [tick-borne rickettsioses]) a billable code?

No. This is a category header that groups the codes for spotted fever [tick-borne rickettsioses], and headers cannot be submitted on claims. Claims for spotted fever [tick-borne rickettsioses] need a more specific code from this category, such as A77.0, A77.1, and A77.2.