Is A04 a billable ICD-10-CM code?

No. A04 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does A04 sit in the tabular list?

Certain infectious and parasitic diseases (A00-B99), in the block Intestinal infectious diseases (A00-A09).

What cannot be coded together with A04?

A04 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

A04

A04 — Other bacterial intestinal infections

Non-billable headerICD-10-CM

A04 is a non-billable header ICD-10-CM code for other bacterial intestinal infections. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

bacterial foodborne intoxications, NEC (A05.-)
tuberculous enteritis (A18.32)

Other codes that can never be billed with A04

These codes carry an Excludes1 note pointing at A04. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A04 alone.

A05Other bacterial foodborne intoxications, not elsewhere classified
A28.2Extraintestinal yersiniosis
K59.3Megacolon, not elsewhere classified

Risk adjustment

A04 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 A04

10 child codes. Green means billable.

Questions about A04

Is A04 a billable ICD-10-CM code?: No. A04 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does A04 sit in the tabular list?: Certain infectious and parasitic diseases (A00-B99), in the block Intestinal infectious diseases (A00-A09).
What cannot be coded together with A04?: A04 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.