T18.100D ICD-10-CM Code: Unspecified foreign body in esophagus causing compression of trachea, subsequent encounter

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for T18.100D in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on T18.100D itself; “inherited from” names the category or block whose note applies here.

7th Character Guide

"The appropriate 7th character is to be added to each code from category T18"

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

T18.100A, T18.100D, T18.100S

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 T18.100D

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

Before you code T18.100D

1. Unspecified does not mean incorrect. When the record gives no greater specificity, T18.100D may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

   See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

2. 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 “D”. “Initial” means active treatment, not the first visit (Guidelines I.C.19.a).

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

3. Confirm the injury type, the anatomical site at the most specific level documented, laterality where the family codes it, and the encounter for the 7th character. Each injury is coded separately unless the classification provides a combination code, and a superficial injury is not coded when a more severe injury of the same site is documented. Injury chapter guidelines (Guidelines I.C.19.b, I.C.19.b.1).

   Guide: 7th characters: initial, subsequent, sequela →

Choose the right path

1. Does the record document the detail a more specific sibling code needs?
   Yes → Review the specific siblings in this subcategory.
   No → Continue — T18.100D is appropriate when the documentation goes no further.
2. 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 T18.100D. Then work the Use Additional Code note, and 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).

Anatomical site

At the most specific level the record states; a site the classification separates cannot be assumed from a procedure or a measurement.

Encounter type

Active treatment, healing or recovery phase, or sequela — the basis of the 7th character (Guidelines I.C.19.a).

The conditions the Use Additional Code note names

Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

External cause, place and activity

For the external cause codes reported with the injury or poisoning, where documented (Guidelines I.C.20.a).

Any detail beyond this code’s title

What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

• Excludes2 — not part of T18.100D(6 notes)

  Coding workflow: The conditions named in this note are not included in T18.100D. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareT17, T17.2, T81.5, M79.5

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

• Use Additional Code — after identifying T18.100D(1 note)

  Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with T18.100D when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

  ReviewW44

  See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

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

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.

Indexed Clinical Terms (1)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

• Foreign body, esophagus, causing, tracheal compression

Don’t confuse T18.100D with…

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

The codes most likely to be picked instead of T18.100D — 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.

• T18.100A— 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 initial encounter moves the case to T18.100A.

  Full comparison: T18.100D vs T18.100A →

• T18.100S— 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 T18.100S.

  Full comparison: T18.100D vs T18.100S →

• T17— 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 foreign body in respiratory tract adds T17; it is not part of this code and both may be reported when both are documented.

  Full comparison: T18.100D vs T17 →

• T17.2— 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 foreign body in pharynx adds T17.2; it is not part of this code and both may be reported when both are documented.

  Full comparison: T18.100D vs T17.2 →

• T81.5— 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 foreign body accidentally left in operation wound adds T81.5; it is not part of this code and both may be reported when both are documented.

  Full comparison: T18.100D vs T81.5 →

• M79.5— 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 residual foreign body in soft tissue adds M79.5; it is not part of this code and both may be reported when both are documented.

  Full comparison: T18.100D vs M79.5 →

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.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

1. A 7th character applies in this family. Confirm the documented encounter matches the character assigned. See the official 7th-character definitions and this code’s variants
2. 1 Use Additional Code instruction — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
3. 6 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

• No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

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 structured relationships — computed from published CMS and AHRQ datasets

Other codes that name T18.100D or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: Z18 — Retained foreign body fragments (via T18.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 1 Use Additional Code instruction: T56 — Toxic effect of metals (via T18.1.-).

These codes instruct coders to additionally report this code when it applies.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

Not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity.

Named in the grouper logic of 2 MS-DRGs: DRG 949 (MDC 23), DRG 950 (MDC 23).

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

Clinical classification (AHRQ CCSR):INJ057 — Effect of foreign body entering opening, subsequent encounter (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 injury, other encounter phase

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

T18.100A — Unspecified foreign body in esophagus causing compression of trachea, initial encounterCompare T18.100D vs T18.100A →, T18.100S — Unspecified foreign body in esophagus causing compression of trachea, sequela

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Effect of foreign body entering opening, subsequent encounter).

T17.898D — Other foreign object in other parts of respiratory tract causing other injury, subsequent encounter, T17.900D — Unspecified foreign body in respiratory tract, part unspecified causing asphyxiation, subsequent encounter, T17.908D — Unspecified foreign body in respiratory tract, part unspecified causing other injury, subsequent encounter, T17.910D — Gastric contents in respiratory tract, part unspecified causing asphyxiation, subsequent encounter, T17.918D — Gastric contents in respiratory tract, part unspecified causing other injury, subsequent encounter, T17.920D — Food in respiratory tract, part unspecified causing asphyxiation, subsequent encounter, T17.928D — Food in respiratory tract, part unspecified causing other injury, subsequent encounter, T17.990D — Other foreign object in respiratory tract, part unspecified in causing asphyxiation, subsequent encounter, T17.998D — Other foreign object in respiratory tract, part unspecified causing other injury, subsequent encounter, T18.0XXD — Foreign body in mouth, subsequent encounter, T18.108D — Unspecified foreign body in esophagus causing other injury, subsequent encounter, T18.110D — Gastric contents in esophagus causing compression of trachea, subsequent encounter, T18.118D — Gastric contents in esophagus causing other injury, subsequent encounter, T18.120D — Food in esophagus causing compression of trachea, subsequent encounter, T18.128D — Food in esophagus causing other injury, subsequent encounter, T18.190D — Other foreign object in esophagus causing compression of trachea, subsequent encounter, T18.198D — Other foreign object in esophagus causing other injury, subsequent encounter, T18.2XXD — Foreign body in stomach, subsequent encounter, T18.3XXD — Foreign body in small intestine, subsequent encounter, T18.4XXD — Foreign body in colon, subsequent encounter, +66 more

Contextual Map

Every relationship of T18.100D 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.

Run T18.100D with these 2 related codes in Claim Check

Hierarchy

• S00-T88 — Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) (S00-T88)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T15-T19 — Effects of foreign body entering through natural orifice[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• Z18 — Retained foreign body fragments[Excludes1](via T18.-): “foreign body entering through orifice (T15-T19)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Use Additional Code instructions

• T56 — Toxic effect of metals[Use Additional Code](via T18.1.-): “code to identify any retained metal foreign body, if applicable (Z18.0-, T18.1-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• INJ057 — Effect of foreign body entering opening, subsequent encounter[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• DRG 949 — AFTERCARE WITH CC/MCC[MS-DRG]: “AFTERCARE WITH CC/MCC (MDC 23)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 950 — AFTERCARE WITHOUT CC/MCC[MS-DRG]: “AFTERCARE WITHOUT CC/MCC (MDC 23)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 23 — Factors Influencing Health Status and Other Contacts with Health Services[MDC crossing]: “Factors Influencing Health Status and Other Contacts with Health Services — 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. 1,235 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Foreign body, esophagus, causing, tracheal compression[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (40)

• T18 — Foreign body in alimentary tract[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.0 — Foreign body in mouth[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.0XXA — Foreign body in mouth, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.0XXD — Foreign body in mouth, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.0XXS — Foreign body in mouth, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.1 — Foreign body in esophagus[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.10 — Unspecified foreign body in esophagus[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.100 — Unspecified foreign body in esophagus causing compression of trachea[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 32 more

Change history

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

Common coding questions

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 FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 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 — v43 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 structured 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 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.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T18.100D in its code family, with their registry titles.

• T18.0XXS — Foreign body in mouth, sequela
• T18.1 — Foreign body in esophagus
• T18.10 — Unspecified foreign body in esophagus
• T18.100 — Unspecified foreign body in esophagus causing compression of trachea
• T18.100A — Unspecified foreign body in esophagus causing compression of trachea, initial encounter
• T18.100S — Unspecified foreign body in esophagus causing compression of trachea, sequela
• T18.108 — Unspecified foreign body in esophagus causing other injury
• T18.108A — Unspecified foreign body in esophagus causing other injury, initial encounter
• T18.108D — Unspecified foreign body in esophagus causing other injury, subsequent encounter
• T18.108S — Unspecified foreign body in esophagus causing other injury, sequela

View all codes in the T18 family