2026 ICD-10-CM Diagnosis Code I31.4Cardiac tamponade
ICD-10-CM Codes›I00–I99›I30-I5A›I31
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not a Principal Diagnosis
- Not Chronic
I31.4 is a billable ICD-10-CM diagnosis code for cardiac tamponade. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 17 closely related codes. The code is not accepted as a principal diagnosis by the Medicare Code Editor. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pericarditis and pericardial disease.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for I31.4.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Cardiac tamponade
- Postoperative cardiac tamponade
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Code First
- underlying cause
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Tamponade, heart I31.4
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Cardiac Tamponade
compression of the heart by accumulated fluid (pericardial effusion) or blood (hemopericardium) in the pericardium surrounding the heart. the affected cardiac functions and cardiac output can range from minimal to total hemodynamic collapse.
Patient EducationClinical
Pericardial Disorders
The pericardium is a membrane, or sac, that surrounds your heart. It holds the heart in place and helps it work properly. Problems with the pericardium include:
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Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert I31.4 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About I31.4Overview
What is the ICD-10 code for cardiac tamponade?
The ICD-10-CM code for cardiac tamponade is I31.4 (sometimes written as I314). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is I31.4 (Other diseases of pericardium) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report cardiac tamponade on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does I31.4 group to?
On inpatient claims, cardiac tamponade maps to MS-DRG 314, 315, 316, with relative weights from 0.6821 to 2.0852 depending on complications. Higher weights mean higher Medicare reimbursement.
Is I31.4 a CC or MCC?
CMS lists I31.4 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 17 closely related codes in its exclusion list.
Can I31.4 be a principal diagnosis?
No. The Medicare Code Editor rejects this code as a principal diagnosis because cardiac tamponade describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.
