ICD-10 Code I40.0 – Infective myocarditis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I40.0 – Infective myocarditis
What it is
I40.0 identifies myocarditis caused by infection, meaning inflammation of the heart muscle linked to an infectious process. Use it when the provider documents infective myocarditis specifically.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include chest pain, shortness of breath, arrhythmia, or evidence of myocardial inflammation on clinical evaluation.
When to use this code
Use I40.0 when the record clearly states infective myocarditis or infectious inflammation of the myocardium. The diagnosis should be supported by provider documentation, not by suspicion alone. If the cause is identified differently, check documentation for a more specific code.
Do not use for
Do not use this code for myocarditis without an infectious cause, or when the chart only says “myocarditis” with no further detail. Check documentation if the etiology is unclear.
Coding tip
Confirm the provider links the myocarditis to infection before assigning I40.0.