ICD-9 Code 420.0 - Acute pericarditis in diseases classified elsewhere

ICD-9-CM Diagnosis Code 420.0

Diagnosis Code: 420.0 (Raw: 4200)

Description: Acute pericarditis in diseases classified elsewhere

Classification: International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)

Fiscal Year: 2026 Reference

CMS Section 111 Status: Valid for reporting.

Overview & Historical Usage

ICD-9-CM code 420.0 is designated for Acute pericarditis in diseases classified elsewhere. While superseded by ICD-10 for current healthcare encounters, it remains a recognized reference code for CMS Section 111 reporting, legacy claims adjudication, and historical clinical data analysis.