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S20-S29 vs T17.4

S20-S29 (Injuries to the thorax (S20-S29)) compared with T17.4 (Foreign body in trachea), from the official CMS tabular data.

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

Summary

These codes can be reported together when both conditions are documented, because S20-S29 lists T17.4 under Excludes2, which marks them as distinct conditions.

Official rule
What is different?

The conditions named.S20-S29 is “Injuries to the thorax (S20-S29)”; T17.4 is “Foreign body in trachea”.

Registry fact

Can these codes be reported together?

Yes, when both are documented.S20-S29 lists T17.4 under Excludes2: “effects of foreign body in trachea (T17.4)”. Excludes2 marks distinct conditions that may both be reported when both are documented.

Official ruleGuide: Excludes1 vs Excludes2

Is there an Excludes1 relationship?

None.Neither entry carries an Excludes1 note that names the other code.

Official rule

Is there an Excludes2 relationship?

Yes.S20-S29’s tabular entry: “effects of foreign body in trachea (T17.4)”. The note covers T17.4.

Official ruleGuide: Excludes1 vs Excludes2

Is one more specific?

Not comparable.The codes sit in different categories; specificity is only comparable within one category.

Is one a parent or header code?

Both are headers.Both are non-billable headers, and neither contains the other.

Registry fact

Are there sequencing instructions?

None.Neither entry carries a Code First or Use Additional Code note that names the other.

Official rule

Are there other coding relationships?

None found.No laterality, encounter-phase, Table of Neoplasms, Table of Drugs and Chemicals, or history-versus-active-disease relationship links these codes.

MedCoder-derived

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels

Can these codes be reported together?

Informational

Excludes2 relationship

S20-S29
Injuries to the thorax (S20-S29)
↔
T17.4
Foreign body in trachea

What we found

Yes, when both are documented.S20-S29 carries an Excludes2 note covering T17.4: “effects of foreign body in trachea (T17.4)”

Excludes2 marks distinct conditions — both may be reported when both are documented.

What to review

Report both only when the documentation supports both conditions; otherwise report the one documented.

Guide: Excludes1 vs Excludes2Check these on a claim

Why it matters

An Excludes2 note means the excluded condition is not part of the code above it, but a patient can have both. Report both when both are documented.

Source / rule

CMS ICD-10-CM tabular instructional notes

Official guidance behind these answers

  • Section I.A.12.b — Excludes2 · applies to: Excludes2

    A type 2 Excludes note represents “Not included here.” An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

    ICD-10-CM Official Guidelines FY2027

Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum

Side by side

S20-S29Injuries to the thorax (S20-S29)T17.4Foreign body in trachea
Billing statusNon-billable headerNon-billable header

Report instead: T17.400A, T17.400D, T17.400S, T17.408A, T17.408D

ClassificationS00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)
DefinitionInjuries to the thorax (S20-S29) is a non-billable ICD-10-CM category code (S20-S29).Foreign body in trachea is a non-billable ICD-10-CM category code (T17.4).
7th character—The appropriate 7th character is to be added to each code from category T17
Includes
injuries of breast
injuries of chest (wall)
injuries of interscapular area
—
Excludes2
burns and corrosions (T20-T32)
effects of foreign body in bronchus (T17.5)
effects of foreign body in esophagus (T18.1)
effects of foreign body in lung (T17.8)
effects of foreign body in trachea (T17.4)
frostbite (T33-T34)
injuries of axilla
injuries of clavicle
injuries of scapular region
injuries of shoulder
insect bite or sting, venomous (T63.4)
foreign body accidentally left in operation wound (T81.5-)
foreign body in penetrating wound - See open wound by body region
residual foreign body in soft tissue (M79.5)
splinter, without open wound - See superficial injury by body region
Use additional code—
code, if known, for foreign body entering into or through a natural orifice (W44.-)

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on.

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Derived from the official CMS ICD-10-CM tabular data (FY2027). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources