Skip to content
Dx

ICD-10-CM 2027 diagnosis code

A31Infection due to other mycobacteria

Not billable — use a more specific code

A31 is a header code, so it can't be reported by itself. Choose one of the 5 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About A31

A31 is the ICD-10-CM diagnosis code for infection due to other mycobacteria. It belongs to block A30-A49 (other bacterial diseases) and chapter 1 (certain infectious and parasitic diseases). It is a header code, so it can't be reported by itself; one of its 5 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: A31.0 (infection), A31.1 (infection), A31.2 ((DMAC)), A31.8 (infections) and A31.9 (unspecified).

The conditions in its Excludes2 note aren't part of A31, but may be coded alongside it if the patient has both: leprosy (A30.-) and tuberculosis (A15-A19).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under A31

Coding notes

Excludes2Not included here — may be reported together if both conditions exist

Notes that apply from higher levels

Instructions written at a parent level also apply to A31.

Broader instructions also apply from Chapter 1: Certain infectious and parasitic diseases.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about A31

Is A31 billable?

No. A31 is a header code. Report one of its more specific subcodes instead.