2027 ICD-10-CM Diagnosis Code T79.8XXAOther early complications of trauma, initial encounter

ICD-10-CM Codes›S00–T88›T79›T79

ICD-10-CM T79.8XXA
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T79.8XXA is a billable ICD-10-CM diagnosis code for other early complications of trauma, 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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 922 through 923, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified injury.

T79.8XXA no longer risk-adjusts for Medicare Advantage: it mapped to HCC 173 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 173, ESRD (V21) category 173, and ESRD (V24) category 173 for payment year 2027.

Code Identity

ICD-10-CM Code
T79.8XXA
Billable Status
Yes — Valid for Submission
Code Describes
Other early complications of trauma, initial encounter
Short Description
Other early complications of trauma, initial encounter
Same as the full description in the CMS dataset.
Parent Code
T79.8
Other early complications of trauma

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT79Certain early complications of trauma
CategoryT79Certain early complications of trauma, not elsewhere classified
This CodeT79.8XXAOther early complications of trauma, initial encounter

Medicare Risk Adjustment (HCC)Billing

T79.8XXA no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 173
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
Other CMS Models
PACE (CMS-HCC V22): HCC 173 · ESRD (V21): HCC 173 · ESRD (V24): HCC 173
ESRD V21 weights: 0.042 dialysis, 0.061–0.290 functioning graft · ESRD V24 weights: 0.050 dialysis, 0.000–0.341 functioning graft
Part D (RxHCC)
Not mapped
T79.8XXA does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acquired hypotonia
  • Acute confusional state, post-traumatic
  • Acute traumatic otitis externa
  • Acute-on-chronic respiratory failure
  • Acute-on-chronic respiratory failure following trauma
  • Alopecia due to friction and trauma
  • Anemia due to mechanical damage
  • Cerebrospinal fluid otorrhea
  • Chronic respiratory failure
  • Compression injury of nerve
  • Contracture of gastrocnemius muscle due to traumatic injury
  • Irritation of presacral tissue by content of ruptured viscera
  • Lymphedema due to trauma
  • Mucosal vesicle
  • Posttraumatic aphasia
  • Post-traumatic cerebrospinal otorrhea
  • Post-traumatic dementia with behavioral change
  • Post-traumatic eczema
  • Post-traumatic epilepsy
  • Post-traumatic hydrocele
  • Posttraumatic meningitis
  • Post-traumatic nerve entrapment
  • Post-traumatic scar
  • Post-traumatic sterility
  • Respiratory failure following trauma
  • Secondary eczematous condition
  • Sterility
  • Traumatic encephalopathy
  • Traumatic fat necrosis
  • Traumatic hemolytic anemia
  • Traumatic hypotonia
  • Traumatic iritis
  • Traumatic oral hemorrhagic bulla
  • Traumatic pneumonitis
  • Ulcer of mouth due to trauma
  • Vesicular stomatitis

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 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to T79.8XXA: its own notes plus those printed at T79 and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From T79 Certain early complications of trauma, not elsewhere classified applies to 54 codes
  • acute respiratory distress syndrome (J80)
  • complications occurring during or following medical procedures (T80-T88)
  • complications of surgical and medical care NEC (T80-T88)
  • newborn respiratory distress syndrome (P22.0)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Notes

General instructions on how these codes are used.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From T79 Certain early complications of trauma, not elsewhere classified applies to 54 codes
  • The appropriate 7th character is to be added to each code from category T79
Values for category T79 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter this code
  • Dsubsequent encounter
  • Ssequela

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ026
Other specified injury
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Wounds and Injuries

An injury is damage to your body. It is a general term that refers to harm caused by accidents, falls, hits, weapons, and more. In the U.S., millions of people injure themselves every year. These injuries range from minor to life-threatening.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert T79.8XXA to ICD-9-CMHistory

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

ICD-9-CM
958.8 Early complic trauma NEC
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About T79.8XXAOverview

What is the ICD-10 code for other early complications of trauma, initial encounter?

The ICD-10-CM code for other early complications of trauma, initial encounter is T79.8XXA (sometimes written as T798XXA). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is T79.8XXA (Other early complications of trauma) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other early complications of trauma, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in T79.8XXA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for other early complications of trauma, such as an emergency visit or first evaluation.

What MS-DRG does T79.8XXA group to?

When other early complications of trauma, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 964, 923, 965, 922, 963, with relative weights from 0.9980 to 2.6361 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of T79.8XXA?

Under the General Equivalence Mappings, other early complications of trauma, initial encounter converts to ICD-9-CM 958.8 (early complic trauma NEC). The mapping is approximate, so confirm the match fits the documentation.

Does T79.8XXA risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. T79.8XXA mapped to HCC 173 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 173 (Traumatic Amputations and Complications), ESRD (V21) category 173 (Traumatic Amputations and Complications), and ESRD (V24) category 173 (Traumatic Amputations and Complications).