Is I40 a billable ICD-10-CM code?

No. I40 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does I40 sit in the tabular list?

Diseases of the circulatory system (I00-I99), in the block Other forms of heart disease (I30-I5A).

What cannot be coded together with I40?

I40 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

I40

I40 — Acute myocarditis

Non-billable headerICD-10-CM

I40 is a non-billable header ICD-10-CM code for acute myocarditis. 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.

acute rheumatic myocarditis (I01.2)

Includes

Conditions this code covers.

subacute myocarditis

Other codes that can never be billed with I40

These codes carry an Excludes1 note pointing at I40. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading I40 alone.

I51.4Myocarditis, unspecified

Risk adjustment

I40 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 I40

4 child codes. Green means billable.

Questions about I40

Is I40 a billable ICD-10-CM code?: No. I40 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does I40 sit in the tabular list?: Diseases of the circulatory system (I00-I99), in the block Other forms of heart disease (I30-I5A).
What cannot be coded together with I40?: I40 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.