2026 ICD-10-CM Diagnosis Code A31Infection due to other mycobacteria

ICD-10-CM Codes›A00–B99›A30-A49›A31

ICD-10-CM A31
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A31 is a non-billable ICD-10-CM category code for infection due to other mycobacteria, so it cannot be submitted on claims. Use a more specific code from this category instead, such as A31.0, A31.1, A31.2, and A31.8.

Code Identity

ICD-10-CM Code
A31
Billable Status
No — Non-Billable Category
Code Describes
Infection due to other mycobacteria
Chapter
A30-A49
Other bacterial diseases

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA30-A49Other bacterial diseases
CategoryA31Infection due to other mycobacteria
This CodeA31Infection due to other mycobacteria

Specific Coding for Infection due to other mycobacteriaOverview

Non-specific codes like A31 require more characters. Use one of these billable codes instead:

  • Use A31.0 for Pulmonary mycobacterial infection

  • Use A31.1 for Cutaneous mycobacterial infection

  • Use A31.2 for Disseminated mycobacterium avium-intracellulare complex (DMAC)

  • Use A31.8 for Other mycobacterial infections

  • Use A31.9 for Mycobacterial infection, unspecified

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 2 Excludes

Patient EducationClinical

Mycobacterial Infections

Mycobacteria are a type of germ. There are many different kinds. The most common one causes tuberculosis. Another one causes leprosy. Still others cause infections that are called atypical mycobacterial infections. They aren't "typical" because they don't cause tuberculosis.

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 A31Overview

Is A31 (Infection due to other mycobacteria) a billable code?

No. This is a category header that groups the codes for infection due to other mycobacteria, and headers cannot be submitted on claims. Claims for infection due to other mycobacteria need a more specific code from this category, such as A31.0, A31.1, and A31.2.