ICD-10 Code B33.2 – Viral carditis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B33.2 – Viral carditis
What it is
Viral carditis is inflammation of the heart caused by a viral infection. Use this code when documentation identifies viral involvement of the myocardium, pericardium, or both.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include chest pain, palpitations, shortness of breath, fatigue, or evidence of cardiac inflammation on exam or imaging.
When to use this code
Use B33.2 when the provider documents viral carditis, viral myocarditis, or viral pericardial involvement as the confirmed diagnosis. It may also apply when the record clearly links the cardiac inflammation to a viral cause. If the chart only says “carditis” without an infectious cause, check documentation.
Do not use for
Do not use this code for nonviral carditis, ischemic heart disease, or nonspecific chest pain. If the cause is bacterial, autoimmune, or otherwise different, select the documented condition instead.
Coding tip
Code the viral cause only when the provider explicitly documents the link; otherwise, query or use the most specific confirmed diagnosis.