ICD-10 Code I31.9 – Disease of pericardium, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I31.9 – Disease of pericardium, unspecified
What it is
I31.9 identifies a disorder of the pericardium, the sac surrounding the heart, when the documentation does not specify the exact type. Use it when the record confirms pericardial disease but gives no clearer diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Pericardial disease may present with chest pain, shortness of breath, or findings on imaging or echocardiography, but the exact presentation depends on the underlying condition.
When to use this code
Use I31.9 when the provider documents a pericardial disorder without naming a more specific diagnosis, such as effusion, constriction, or inflammation. It also fits when the chart only states “disease of pericardium” or an unspecified pericardial abnormality. Check documentation if another code is supported.
Do not use for
Do not use I31.9 when the record identifies a specific pericardial condition, such as pericarditis or pericardial effusion. Also avoid it if the diagnosis refers to another cardiac structure or a postoperative complication.
Coding tip
Query for the exact pericardial diagnosis before assigning I31.9, because a more specific code is usually available.