ICD-10 Code I30.0 – Acute nonspecific idiopathic pericarditis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I30.0 – Acute nonspecific idiopathic pericarditis
What it is
I30.0 identifies an acute inflammation of the pericardium with no specific cause documented. Use it when the provider describes idiopathic pericarditis and does not name a more specific infectious, autoimmune, or postprocedural cause.
Clinical signs
Typical findings include acute chest pain that may worsen with breathing or lying down, a pericardial friction rub, and evidence of pericardial inflammation. Clinical features vary; refer to documentation.
When to use this code
Use I30.0 when the record states acute nonspecific idiopathic pericarditis and no alternate etiology is documented. It also fits encounters where the clinician confirms pericarditis but documents the cause as unknown or idiopathic.
If the chart later identifies a specific cause, code that condition instead. Check documentation for associated effusion, tamponade, or another pericardial disorder that may require a different code.
Do not use for
Do not use I30.0 when pericarditis is documented as infectious, neoplastic, rheumatic, uremic, postprocedural, or due to another known cause. Do not assign it for chronic pericarditis unless the record clearly says acute.
Coding tip
Use the provider’s stated etiology first; “idiopathic” supports I30.0 only when no specific cause is documented.