2026 ICD-10-CM Diagnosis Code S26.90XAUnspecified injury of heart, unspecified with or without hemopericardium, initial encounter
S26.90XA is a billable ICD-10-CM diagnosis code for unspecified injury of heart, unspecified with or without hemopericardium, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. 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, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Internal organ injury, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acquired ventricular septal defect
- Heart injury, closed
- Heart injury, open
- Injury of cardiac valve
- Injury of heart
- Injury of heart with open wound into thorax
- Injury of heart without open wound into thorax
- Injury of pericardium
- Injury of thoracic cavity
- Injury to heart and lung
- Pericarditis secondary to penetrating trauma
- Pneumopericardium
- Post-cardiac injury syndrome
- Post-traumatic pericarditis
- Trauma to aortic valve
- Trauma to mitral valve
- Trauma to pulmonary valve
- Trauma to tricuspid valve
- Traumatic interventricular septal defect
- Traumatic pneumopericardium
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of heart (S26). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Pneumopericardium
presence of air or gas in the space between the heart and the pericardium. the degree of respiratory distress depends on the amount of trapped air and circulation blocked in the systemic and pulmonary veins.Pericardium
a conical fibro-serous sac surrounding the heart and the roots of the great vessels (aorta; venae cavae; pulmonary artery). pericardium consists of two sacs: the outer fibrous pericardium and the inner serous pericardium. the latter consists of an outer parietal layer facing the fibrous pericardium, and an inner visceral layer (epicardium) resting next to the heart, and a pericardial cavity between these two layers.Pneumopericardium
the presence of air in the pericardial cavity. causes include chest injury in adults, and respiratory distress syndrome in infants.
Patient EducationClinical
Chest Injuries and Disorders
The chest is the part of your body between your neck and your abdomen (belly). The medical term for your chest is thorax.
The full article covers:
- What is the chest?
- What are chest injuries and disorders?
- How are chest injuries and disorders diagnosed?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S26.90XA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S26.90XAOverview
Is S26.90XA a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified injury of heart, unspecified with or without hemopericardium, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S26.90XA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for unspecified injury of heart, unspecified with or without hemopericardium, such as an emergency visit or first evaluation.
What MS-DRG does S26.90XA group to?
When unspecified injury of heart, unspecified with or without hemopericardium, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, 963, 964, 965, with relative weights from 0.6821 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S26.90XA?
Under the General Equivalence Mappings, unspecified injury of heart, unspecified with or without hemopericardium, initial encounter converts to ICD-9-CM 861.00 (heart injury NOS-closed). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
