2026 ICD-10-CM Diagnosis Code T79.1XXAFat embolism (traumatic), initial encounter
T79.1XXA is a billable ICD-10-CM diagnosis code for fat embolism (traumatic), 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 175 through 176, 963 through 965. Coders also document this condition as early complication of trauma. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified injury.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Early complication of trauma
- Fat embolism
- Fat embolism - obstetric
- Fat embolism as early complication of trauma
- Fulminant fat embolism syndrome
- Obstetric pulmonary embolism
- Pulmonary fat embolism
- Subacute pulmonary fat embolism
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Certain early complications of trauma, not elsewhere classified (T79). 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.
Convert T79.1XXA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T79.1XXAOverview
Is T79.1XXA (Fat embolism (traumatic)) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report fat embolism (traumatic), initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T79.1XXA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for fat embolism (traumatic), such as an emergency visit or first evaluation.
What MS-DRG does T79.1XXA group to?
When fat embolism (traumatic), initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 175, 176, 963, 964, 965, with relative weights from 0.8050 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of T79.1XXA?
Under the General Equivalence Mappings, fat embolism (traumatic), initial encounter converts to ICD-9-CM 958.1 (fat embolism). 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.
