ICD-10 Code B33.22 – Viral myocarditis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B33.22 – Viral myocarditis
What it is
B33.22 identifies myocarditis caused by a viral infection. Use it when the record documents inflammation of the heart muscle attributed to a virus.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include chest pain, dyspnea, palpitations, arrhythmia, or signs of heart failure, with supportive imaging or cardiac testing.
When to use this code
Use B33.22 when the provider clearly links myocarditis to a viral cause. It is appropriate for confirmed viral myocarditis, including cases described as acute or unspecified viral myocarditis if no more specific code is documented.
If the note only says “myocarditis” without an infectious cause, check documentation before coding this diagnosis.
Do not use for
Do not use this code for nonviral myocarditis, cardiomyopathy, or chest pain without documented myocarditis. Check documentation when the cause is unclear or when myocarditis is only suspected.
Coding tip
Look for explicit provider wording that ties myocarditis to a viral infection before assigning B33.22.