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A21

A21Tularemia

Non-billable headerICD-10-CM

A21 is a non-billable header ICD-10-CM code for tularemia. It cannot be billed on its own: choose one of the more specific child codes below.

Includes

Conditions this code covers.

  • deer-fly fever
  • infection due to Francisella tularensis
  • rabbit fever

Other codes that can never be billed with A21

These codes carry an Excludes1 note pointing at A21. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A21 alone.

  • J17Pneumonia in diseases classified elsewhere

Risk adjustment

A21 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead A21

7 child codes. Green means billable.

Questions about A21

Is A21 a billable ICD-10-CM code?
No. A21 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does A21 sit in the tabular list?
Certain infectious and parasitic diseases (A00-B99), in the block Certain zoonotic bacterial diseases (A20-A28).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.