2026 ICD-10-CM Diagnosis Code A27Leptospirosis

ICD-10-CM Codes›A00–B99›A20-A28›A27

ICD-10-CM A27
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A27 is a non-billable ICD-10-CM category code for leptospirosis, so it cannot be submitted on claims. Use a more specific code from this category instead, such as A27.0, A27.81, A27.89, and A27.9.

Code Identity

ICD-10-CM Code
A27
Billable Status
No — Non-Billable Category
Code Describes
Leptospirosis
Chapter
A20-A28
Certain zoonotic bacterial diseases

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA20-A28Certain zoonotic bacterial diseases
CategoryA27Leptospirosis
This CodeA27Leptospirosis

Specific Coding for LeptospirosisOverview

Non-specific codes like A27 require more characters. Use one of these billable codes instead:

  • Use A27.0 for Leptospirosis icterohemorrhagica

  • A27.8 for Other forms of leptospirosis

  • Use A27.81 for Aseptic meningitis in leptospirosis

  • Use A27.89 for Other forms of leptospirosis

  • Use A27.9 for Leptospirosis, unspecified

Clinical InformationClinical

  • Leptospirosis

    infections with bacteria of the genus leptospira.

  • Weil Disease

    a severe form of leptospirosis, usually caused by leptospira interrogans serovar icterohaemorrhagiae and occasionally other serovars. it is transmitted to humans by the rat and is characterized by hemorrhagic and renal symptoms with accompanying jaundice.

  • Leptospira

    a genus of aerobic, helical spirochetes, some species of which are pathogenic, others free-living or saprophytic.

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 A27Overview

Is A27 (Leptospirosis) a billable code?

No. This is a category header that groups the codes for leptospirosis, and headers cannot be submitted on claims. Claims for leptospirosis need a more specific code from this category, such as A27.0, A27.81, and A27.89.