2026 ICD-10-CM Diagnosis Code I41Myocarditis in diseases classified elsewhere
ICD-10-CM Codes›I00–I99›I30-I5A›I41
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Not Chronic
I41 is a billable ICD-10-CM diagnosis code for myocarditis in diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316, 791, 793. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 22 closely related codes. The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Myocarditis and cardiomyopathy.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for I41.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute myocarditis
- Acute myocarditis associated with another disorder
- Chagas' disease with heart involvement
- Chronic Chagas' disease
- Congenital rubella syndrome
- Heart disease co-occurrent with human immunodeficiency virus infection
- Myocarditis co-occurrent with human immunodeficiency virus infection
- Myocarditis due to autoimmune disease
- Myocarditis due to Chaga disease
- Myocarditis due to childhood type dermatomyositis
- Myocarditis due to COVID-19
- Myocarditis due to hypersensitivity state
- Myocarditis due to idiopathic hypereosinophilic syndrome
- Myocarditis due to Kawasaki disease
- Parasitic myocarditis
- Protozoan myocarditis
- Rubella myocarditis
- Subacute myocarditis with AIDS
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Code First
Type 1 Excludes
- myocarditis (in):
- Chagas' disease chronic B57.2
- acute B57.0
- coxsackie virus infection B33.22
- diphtheritic A36.81
- gonococcal A54.83
- influenzal J09.X9 J10.82 J11.82
- meningococcal A39.52
- mumps B26.82
- rheumatoid arthritis M05.31
- sarcoid D86.85
- syphilis A52.06
- toxoplasmosis B58.81
- tuberculous A18.84
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Acute Myocarditis
the sudden onset of inflammation of heart muscle with myocellular necrosis; this is generally secondary to an infectious cause, and patients often have a recent history of a flu-like illness.
Patient EducationClinical
Cardiomyopathy
Cardiomyopathy is the name for diseases of the heart muscle. These diseases enlarge your heart muscle or make it thicker and more rigid than normal. In rare cases, scar tissue replaces the muscle tissue.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert I41 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About I41Overview
What is the ICD-10 code for myocarditis in diseases classified elsewhere?
The ICD-10-CM code for myocarditis in diseases classified elsewhere is I41. It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is I41 (Myocarditis in diseases classified elsewhere) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report myocarditis in diseases classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does I41 group to?
On inpatient claims, myocarditis in diseases classified elsewhere maps to MS-DRG 314, 315, 316, 791, 793, with relative weights from 0.6821 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.
Is I41 a CC or MCC?
CMS lists I41 as an MCC (major complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 22 closely related codes in its exclusion list.
Can I41 be a principal diagnosis?
No. This is a manifestation code: myocarditis in diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
