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T79.7XXA ICD-10-CM Code: Traumatic subcutaneous emphysema, initial encounter

Compare with another codeCheck this code on a claim

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

7th character
Required — see the character table on this page
Tabular directives
6 Excludes2
Risk adjustment
CMS-HCC V22 category 173

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too; the Instructions section marks which is which.

Excludes2Not included here; may be reported together
  • emphysema NOS (J43)
  • emphysema (subcutaneous) resulting from a procedure (T81.82)
  • acute respiratory distress syndrome (J80)
  • complications occurring during or following medical procedures (T80-T88)

+2 more in Instructions

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

CompareCheck ClaimView Related Codes

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v44, Appendix B.

  • MS-DRG 199 — PNEUMOTHORAX WITH MCC (MDC 04)
  • MS-DRG 200 — PNEUMOTHORAX WITH CC (MDC 04)
  • MS-DRG 201 — PNEUMOTHORAX WITHOUT CC/MCC (MDC 04)
  • MS-DRG 791 — PREMATURITY WITH MAJOR PROBLEMS (MDC 15)
  • MS-DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)
  • MS-DRG 963 — OTHER MULTIPLE SIGNIFICANT TRAUMA WITH MCC (MDC 24)
  • MS-DRG 964 — OTHER MULTIPLE SIGNIFICANT TRAUMA WITH CC (MDC 24)
  • MS-DRG 965 — OTHER MULTIPLE SIGNIFICANT TRAUMA WITHOUT CC/MCC (MDC 24)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for T79.7XXA in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on T79.7XXA itself; “inherited from” names the category or block whose note applies here.

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

7th Character Guide

"The appropriate 7th character is to be added to each code from category T79"

  • A — initial encounter (this page’s code)
  • D — subsequent encounter
  • S — sequela

How the encounter character is assigned. “Initial encounter” means the patient is receiving active treatment for the condition — it is not limited to the first visit, and a different or new provider giving active treatment still assigns it. “Subsequent encounter” covers care during the healing or recovery phase after active treatment. “Sequela” is for complications or conditions that arise as a direct result of the original condition.

ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.a (paraphrased by MedCoder).

Variant codes in this family

T79.7XXA, T79.7XXD, T79.7XXS

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Coder workflow for T79.7XXA

MedCoder structured workflow — derived from this code’s own official record

Before you code T79.7XXA

  1. A 7th character is required in this family. Confirm the documented encounter: initial (active treatment), subsequent (healing or recovery phase), or sequela. This page’s code carries “A”. “Initial” means active treatment, not the first visit (Guidelines I.C.19.a).

    See the 7th Character Guide · Guide: 7th characters: initial, subsequent, sequela →

Choose the right path

  1. Is the encounter phase documented — active treatment, healing or recovery, or a sequela?
    Yes → Assign the matching 7th character; the variant codes are in the 7th Character Guide.
    No → The code is invalid without its 7th character — query for the missing element.

Consider T79.7XXA. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Encounter type
Active treatment, healing or recovery phase, or sequela — the basis of the 7th character (Guidelines I.C.19.a).

Official instructions as workflow

  • Excludes2 — not part of T79.7XXA(6 notes)

    Coding workflow: The conditions named in this note are not included in T79.7XXA. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareJ43, T81.82, J80, P22.0

    See the official tabular notes · Guidelines I.A.12.b

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The patient returns during the healing or recovery phase after active treatment of the same condition.

Coding question: Which 7th character applies?

Path: Review the official 7th-character definitions for this family in the 7th Character Guide.

Reason: “Initial encounter” means active treatment, not the first visit; care during recovery takes “subsequent encounter”, and a complication arising from the original condition takes “sequela” (Guidelines I.C.19.a).

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Don’t confuse T79.7XXA with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of T79.7XXA — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • T79.7XXD— Encounter relationship (Review)

    Same underlying diagnosis, different encounter phase.

    The same diagnosis at a different phase of care; one encounter takes one 7th character.

    What moves you there: Documentation of a subsequent encounter moves the case to T79.7XXD.

    Full comparison: T79.7XXA vs T79.7XXD →

  • T79.7XXS— Encounter relationship (Review)

    Same underlying diagnosis, different encounter phase.

    The same diagnosis at a different phase of care; one encounter takes one 7th character.

    What moves you there: Documentation of a sequela moves the case to T79.7XXS.

    Full comparison: T79.7XXA vs T79.7XXS →

  • J43— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of emphysema NOS adds J43; it is not part of this code and both may be reported when both are documented.

    Full comparison: T79.7XXA vs J43 →

  • T81.82— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of emphysema (subcutaneous) resulting from a procedure adds T81.82; it is not part of this code and both may be reported when both are documented.

    Full comparison: T79.7XXA vs T81.82 →

  • J80— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of acute respiratory distress syndrome adds J80; it is not part of this code and both may be reported when both are documented.

    Full comparison: T79.7XXA vs J80 →

  • T80— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of complications occurring during or following medical procedures adds T80; it is not part of this code and both may be reported when both are documented.

    Full comparison: T79.7XXA vs T80 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Traumatic subcutaneous emphysema, initial encounter is a billable ICD-10-CM diagnosis code (T79.7XXA).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Verify Before Coding

  • CC as a secondary diagnosis (FY2027). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder-derived relationships — computed from published CMS and AHRQ datasets

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 162 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 8 MS-DRGs: DRG 199 (MDC 04), DRG 200 (MDC 04), DRG 201 (MDC 04), DRG 791 (MDC 15), DRG 793 (MDC 15), DRG 963 (MDC 24), DRG 964 (MDC 24), DRG 965 (MDC 24).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):INJ026 — Other specified injury (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

S27.898A — Other injury of other specified intrathoracic organs, initial encounter, S27.899A — Unspecified injury of other specified intrathoracic organs, initial encounter, S27.9XXA — Injury of unspecified intrathoracic organ, initial encounter, S28.1XXA — Traumatic amputation (partial) of part of thorax, except breast, initial encounter, S29.021A — Laceration of muscle and tendon of front wall of thorax, initial encounter, S29.029A — Laceration of muscle and tendon of unspecified wall of thorax, initial encounter, T07.XXXA — Unspecified multiple injuries, initial encounter, T14.8XXA — Other injury of unspecified body region, initial encounter, T14.90XA — Injury, unspecified, initial encounter, T14.91XA — Suicide attempt, initial encounter, T79.8XXA — Other early complications of trauma, initial encounter, T79.9XXA — Unspecified early complication of trauma, initial encounter, T79.A0XA — Compartment syndrome, unspecified, initial encounter, T79.A11A — Traumatic compartment syndrome of right upper extremity, initial encounter, T79.A12A — Traumatic compartment syndrome of left upper extremity, initial encounter, T79.A19A — Traumatic compartment syndrome of unspecified upper extremity, initial encounter, T79.A21A — Traumatic compartment syndrome of right lower extremity, initial encounter, T79.A22A — Traumatic compartment syndrome of left lower extremity, initial encounter, T79.A29A — Traumatic compartment syndrome of unspecified lower extremity, initial encounter, T79.A3XA — Traumatic compartment syndrome of abdomen, initial encounter, +141 more

Same injury, other encounter phase

Same injury, coded at a different phase of treatment via the 7th character.

T79.7XXD — Traumatic subcutaneous emphysema, subsequent encounterCompare T79.7XXA vs T79.7XXD →, T79.7XXS — Traumatic subcutaneous emphysema, sequelaCompare T79.7XXA vs T79.7XXS →

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Other specified injury).

S99.819A — Other specified injuries of unspecified ankle, initial encounter, S99.821A — Other specified injuries of right foot, initial encounter, S99.822A — Other specified injuries of left foot, initial encounter, S99.829A — Other specified injuries of unspecified foot, initial encounter, T79.0XXA — Air embolism (traumatic), initial encounter, T79.1XXA — Fat embolism (traumatic), initial encounter, T79.2XXA — Traumatic secondary and recurrent hemorrhage and seroma, initial encounter, T79.4XXA — Traumatic shock, initial encounter, T79.5XXA — Traumatic anuria, initial encounter, T79.6XXA — Traumatic ischemia of muscle, initial encounter, T79.8XXA — Other early complications of trauma, initial encounter, T79.9XXA — Unspecified early complication of trauma, initial encounter, T79.A0XA — Compartment syndrome, unspecified, initial encounter, T79.A11A — Traumatic compartment syndrome of right upper extremity, initial encounter, T79.A12A — Traumatic compartment syndrome of left upper extremity, initial encounter, T79.A19A — Traumatic compartment syndrome of unspecified upper extremity, initial encounter, T79.A21A — Traumatic compartment syndrome of right lower extremity, initial encounter, T79.A22A — Traumatic compartment syndrome of left lower extremity, initial encounter, T79.A29A — Traumatic compartment syndrome of unspecified lower extremity, initial encounter, T79.A3XA — Traumatic compartment syndrome of abdomen, initial encounter, +48 more

Contextual Map

Every relationship of T79.7XXA in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 04 — Diseases and Disorders of the Respiratory System[MDC crossing]: “Diseases and Disorders of the Respiratory System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 4,000 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027
  • MDC 15 — Newborns and Other Neonates with Conditions Originating in Perinatal Period[MDC crossing]: “Newborns and Other Neonates with Conditions Originating in Perinatal Period — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”— CMS MS-DRG Definitions Manual · FY2027

Nearest codes (40)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Common coding questions

MedCoder editorial

Does T79.7XXA require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category T79.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder-derived relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder editorial explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 20, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "T79.7XXA — Traumatic subcutaneous emphysema, initial encounter." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/t79.7xxa-traumatic-subcutaneous-emphysema-initial-encounter

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Traumatic subcutaneous emphysema, initial encounter

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T79.7XXA in its code family, with their registry titles.

View all codes in the T79 family