2027 ICD-10-CM Diagnosis Code T79.9XXSUnspecified early complication of trauma, sequela

ICD-10-CM Codes›S00–T88›T79›T79

ICD-10-CM T79.9XXS
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T79.9XXS is a billable ICD-10-CM diagnosis code for unspecified early complication of trauma, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 913 through 914. The code is exempt from POA reporting. Coders also document this condition as avulsion of maxillary vestibule. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.

Code Identity

ICD-10-CM Code
T79.9XXS
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified early complication of trauma, sequela
Short Description
Unspecified early complication of trauma, sequela
Same as the full description in the CMS dataset.
Parent Code
T79.9
Unspecified early complication 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 CodeT79.9XXSUnspecified early complication of trauma, sequela

Present on Admission (POA)Billing

T79.9XXS is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Certain early complications of trauma (T79).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Avulsion of maxillary vestibule
  • Complex laceration of tongue
  • Complication of injury
  • Contaminated complex laceration of tongue
  • Early complication of trauma
  • Laceration of tongue
  • Late effect of complications of trauma
  • Late effect of tendon injury
  • Traumatic complication of injury

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 T79.9XXS: 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
  • Dsubsequent encounter
  • Ssequela this code

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 INJ073
Injury, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

Convert T79.9XXS to ICD-9-CMHistory

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

ICD-9-CM
908.6 Late eff complic trauma
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 T79.9XXSOverview

What is the ICD-10 code for unspecified early complication of trauma, sequela?

The ICD-10-CM code for unspecified early complication of trauma, sequela is T79.9XXS (sometimes written as T799XXS). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is T79.9XXS (Unspecified early complication of trauma) a billable code?

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

What does the 7th character S in T79.9XXS mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the unspecified early complication of trauma itself has resolved, not the original event.

What MS-DRG does T79.9XXS group to?

When unspecified early complication of trauma, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 914, 913, with relative weights from 0.9281 to 1.5448 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T79.9XXS exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for unspecified early complication of trauma, sequela on inpatient claims. The code appears in the Certain early complications of trauma (T79) range of the CMS exempt list.