ICD-10-CM 2027 diagnosis code

A21Tularemia

Not billable — use a more specific code

A21 is a header code, so it can't be reported by itself. Choose one of the 7 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 A21

A21 is the ICD-10-CM diagnosis code for tularemia. It belongs to block A20-A28 (certain zoonotic 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 7 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: A21.0 (tularemia), A21.1 (tularemia), A21.2 (tularemia), A21.3 (tularemia), A21.7 (tularemia), A21.8 (tularemia) and A21.9 (unspecified).

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 A21

Coding notes

IncludesFurther defines the content of the category

deer-fly fever
infection due to Francisella tularensis
rabbit fever

Notes that apply from higher levels

Instructions written at a parent level also apply to A21.

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

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about A21

Is A21 billable?: No. A21 is a header code. Report one of its more specific subcodes instead.