Is A08.1 a billable ICD-10-CM code?

No. A08.1 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does A08.1 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 A08.1?

A08.1 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above A08.1 (A08) and apply to it just the same.

A08.1

A08.1 — Acute gastroenteropathy due to Norwalk agent and other small round viruses

Non-billable headerICD-10-CM

A08.1 is a non-billable header ICD-10-CM code for acute gastroenteropathy due to norwalk agent and other small round viruses. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 inherited from the categories above A08.1

These are not written on A08.1, but they bind it: a note on a category applies to every code beneath it. Billing A08.1 with anything listed here is a denial.

Written on A08 — Viral and other specified intestinal infections

influenza with involvement of gastrointestinal tract (J09.X3, J10.2, J11.2)

Other codes that can never be billed with A08.1

These codes carry an Excludes1 note pointing at A08.1. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A08.1 alone.

J09.X3Influenza due to identified novel influenza A virus with gastrointestinal manifestations
J10.2Influenza due to other identified influenza virus with gastrointestinal manifestations
J11.2Influenza due to unidentified influenza virus with gastrointestinal manifestations

Risk adjustment

A08.1 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 history

A08.1 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Code to one of these instead A08.1

2 child codes. Green means billable.

Related codes at this level

Codes that share A08. If A08.1 is not quite right, the correct code is usually one of these.

Questions about A08.1

Is A08.1 a billable ICD-10-CM code?: No. A08.1 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does A08.1 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 A08.1?: A08.1 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above A08.1 (A08) and apply to it just the same.