2026 ICD-10-CM Diagnosis Code S26.99XAOther injury of heart, unspecified with or without hemopericardium, initial encounter

ICD-10-CM Codes›S00–T88›S20-S29›S26

ICD-10-CM S26.99XA
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S26.99XA is a billable ICD-10-CM diagnosis code for other 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. Coders also document this condition as perforation of cardiac wall due to and following procedure. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Internal organ injury, initial encounter.

Code Identity

ICD-10-CM Code
S26.99XA
Billable Status
Yes — Valid for Submission
Code Describes
Other injury of heart, unspecified with or without hemopericardium, initial encounter
Short Description
Inj heart, unsp w or w/o hemopericardium, init encntr
Parent Code
S26.99
Other injury of heart, unspecified with or without hemopericardium

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS20-S29Injuries to the thorax
CategoryS26Injury of heart
This CodeS26.99XAOther injury of heart, unspecified with or without hemopericardium, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Perforation of cardiac wall due to and following procedure

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.

CCSR INJ010
Internal organ injury, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

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 S26.99XA to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
861.00 Heart injury NOS-closed
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S26.99XAOverview

Is S26.99XA a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other 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 S26.99XA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for other injury of heart, unspecified with or without hemopericardium, such as an emergency visit or first evaluation.

What MS-DRG does S26.99XA group to?

When other 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 S26.99XA?

Under the General Equivalence Mappings, other 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.