I31.31

Billable code

Malignant pericardial effusion in diseases classified elsewhere

The ICD-10 code for malignant pericardial effusion in diseases classified elsewhere is I31.31.

Clinical notes

Code first

This code represents a manifestation of an underlying disease. Coding convention requires the underlying (etiology) code to be sequenced first, with this code listed second.

underlying neoplasm (C00-D49)

Documentation support

General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.

•This code represents a manifestation. Documentation should identify the underlying condition, which must be coded first.
•As a general rule, code to the highest level of specificity supported by the documentation in the medical record.

Related codes in this category

I31.39Other pericardial effusion (noninflammatory)
I31.31Malignant pericardial effusion in diseases classified elsewhere

Associated MS-DRGs

I31.31 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.

Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.