ICD-10 Code I31.3 – Pericardial effusion (noninflammatory) (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I31.3 – Pericardial effusion (noninflammatory)
What it is
I31.3 identifies fluid accumulation in the pericardial sac that is not described as inflammatory. Use it when the record documents a pericardial effusion without evidence of pericarditis or another inflammatory cause.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include an incidental imaging report, enlarged cardiac silhouette, or symptoms related to cardiac compression when the effusion is significant.
When to use this code
Use I31.3 when the provider documents pericardial effusion and does not describe it as inflammatory or as part of acute pericarditis. It may also fit when echocardiography or other imaging confirms effusion and the note supports a noninflammatory cause. Check documentation if the cause is unclear.
Do not use for
Do not use this code for acute pericarditis, pericardial tamponade, or other documented inflammatory pericardial disease. If the effusion is linked to a specific underlying condition, code that condition when instructed.
Coding tip
Verify that the record states “noninflammatory” or gives no inflammatory diagnosis before assigning I31.3.