I40 ICD-10-CM Code: Acute myocarditis
A clear reference for the official code description, hierarchy, and related coding information from the FY 2027 U.S. release.
Official description
I40Acute myocarditis
ICD-10-CM diagnosis code · United States clinical modification
Where I40 sits
- 1
Chapter 9
Diseases of the circulatory system (I00-I99)
- 2
Section
Other forms of heart disease (I30-I5A)
- 3
Category I40
Acute myocarditis
- 4
Code I40
Acute myocarditis
Codes under I40
I40 is a non-billable category. Choose the child code that best matches the documented diagnosis.
Notes for this code
Inclusion terms
No inclusion terms are listed for I40.
Code first
No “code first” instruction is listed for I40.
Use additional code
No “use additional code” instruction is listed for I40.
Excludes1
Conditions that should not be reported together with this code.
- acute rheumatic myocarditis (I01.2)
Excludes2
Conditions not included here that may be reported separately when present.
No Excludes2 note is listed for I40.
Source and release
- Data release
- U.S. ICD-10-CM · FY 2027
- Effective date
- Oct 1, 2026
- Publisher
- Vero Scribe Inc.
This reference is generated from Vero’s ICD-10-CM description, hierarchy, and code-note dataset. The visible content and structured data share that source.
Frequently asked questions
What does ICD-10-CM code I40 mean?
I40 is the FY 2027 U.S. ICD-10-CM code for “Acute myocarditis.”
Is I40 a billable or specific ICD-10-CM code?
No. I40 has more specific child codes in the FY 2027 reference data. Select the code that matches the documentation and confirm the active code set and payer requirements.
Where is I40 located in ICD-10-CM?
I40 is listed in Chapter 9, Diseases of the circulatory system (I00-I99), within Other forms of heart disease (I30-I5A) (I30–I5A), under category I40, Acute myocarditis.
What coding notes are listed for I40?
No inclusion terms are listed for I40 in this reference record. No code-first instruction is listed. Excludes1 notes: acute rheumatic myocarditis (I01.2). No Excludes2 note is listed.