ICD-10 Code I41 – Myocarditis in diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I41 – Myocarditis in diseases classified elsewhere
What it is
I41 identifies myocarditis when the heart muscle inflammation is due to another underlying disease. You should use it only when the cause is documented as a separate condition.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include evidence of myocarditis plus a documented associated disease, but the record should clearly link the two.
When to use this code
Use I41 when the provider states myocarditis is secondary to, or occurring in, another classified disease. Confirm that the underlying condition is coded separately when required. If the cause is not specified, check documentation before assigning this code.
Do not use for
Do not use I41 for myocarditis without a documented underlying disease. Do not substitute it for primary myocarditis or for nonspecific chest pain, cardiomyopathy, or other heart disorders.
Coding tip
Verify the causal disease in the note and code both the myocarditis and the underlying condition when supported.