ICD-10-CM 2027
ICD-10 code for chronic nonrheumatic pericarditis
From the official ICD-10-CM alphabetic index entry “Pericarditis (with decompensation) (with effusion) › chronic (nonrheumatic)”. Page updated September 29, 2026.
About coding chronic nonrheumatic pericarditis
The ICD-10-CM code for chronic nonrheumatic pericarditis is I31.9 (Disease of pericardium, unspecified). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on I31.9.
Within I31, choose I31.9 (Disease of pericardium, unspecified) only when documentation doesn't support a more specific option: chronic adhesive pericarditis (I31.0), chronic constrictive pericarditis (I31.1), hemopericardium, not elsewhere classified (I31.2), pericardial effusion (noninflammatory) (I31.3), cardiac tamponade (I31.4) and other specified diseases of pericardium (I31.8).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 314 (Other Circulatory System Diagnoses with MCC, relative weight 2.0873), DRG 315 (Other Circulatory System Diagnoses with CC, relative weight 0.9508) and DRG 316 (Other Circulatory System Diagnoses without CC/MCC, relative weight 0.6677), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific chronic nonrheumatic pericarditis codes (official index)
- rheumatic I09.2 — Chronic rheumatic pericarditis
Common questions about chronic nonrheumatic pericarditis ICD-10 codes
What is the ICD-10 code for chronic nonrheumatic pericarditis?
- I31.9 — Disease of pericardium, unspecified. More specific codes apply when the documentation supports them: I09.2.
What is the ICD-10 code for rheumatic chronic nonrheumatic pericarditis?
- I09.2 — Chronic rheumatic pericarditis.
Is I31.9 billable?
- Yes. I31.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I31.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I31.9 as a principal diagnosis.
Is I31.9 a CC or MCC?
- I31.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.