T18.9XXD ICD-10-CM Code: Foreign body of alimentary tract, part unspecified, subsequent encounter

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for T18.9XXD in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on T18.9XXD 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

T18.9XXA, T18.9XXD, T18.9XXS

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.

Do Not Confuse With

Codes named in T18.9XXD's own official notes, or sharing its encounter family, with what separates them. Each links to the full comparison.

• T18.9XXA— Encounter relationship (Review)

  Same underlying diagnosis, different encounter phase.

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

  Full comparison: T18.9XXD vs T18.9XXA →

• T18.9XXS— Encounter relationship (Review)

  Same underlying diagnosis, different encounter phase.

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

  Full comparison: T18.9XXD vs T18.9XXS →

• T17.2— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

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

  Full comparison: T18.9XXD 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.

  Full comparison: T18.9XXD 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.

  Full comparison: T18.9XXD vs M79.5 →

Relationships are read from this code's own official notes and its encounter family; the wording of each distinction is MedCoder editorial. 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. 5 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

Other codes that name T18.9XXD 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.

MS-DRG Grouper Relationships (FY2026)

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

Potential MS-DRG participation — not a DRG assignment.

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.

T18.9XXA — Foreign body of alimentary tract, part unspecified, initial encounterCompare T18.9XXD vs T18.9XXA →, T18.9XXS — Foreign body of alimentary tract, part unspecified, 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).

T18.100D — Unspecified foreign body in esophagus causing compression of trachea, 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, T18.5XXD — Foreign body in anus and rectum, subsequent encounter, T18.8XXD — Foreign body in other parts of alimentary tract, subsequent encounter, T19.0XXD — Foreign body in urethra, subsequent encounter, T19.1XXD — Foreign body in bladder, subsequent encounter, T19.2XXD — Foreign body in vulva and vagina, subsequent encounter, T19.3XXD — Foreign body in uterus, subsequent encounter, T19.4XXD — Foreign body in penis, subsequent encounter, T19.8XXD — Foreign body in other parts of genitourinary tract, subsequent encounter, T19.9XXD — Foreign body in genitourinary tract, part unspecified, subsequent encounter, +66 more

Contextual Map

Every relationship of T18.9XXD 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 T18.9XXD with this related code 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

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

Nearest codes (40)

• T18 — Foreign body in alimentary tract[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.120 — Food in esophagus causing compression of trachea[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.120A — Food in esophagus causing compression of trachea, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.120D — Food in esophagus causing compression of trachea, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.120S — Food in esophagus causing compression of trachea, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.128 — Food in esophagus causing other injury[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.128A — Food in esophagus causing other injury, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T18.128D — Food in esophagus causing other injury, subsequent encounter[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 T18.9XXD in its code family, with their registry titles.

• T18.5 — Foreign body in anus and rectum
• T18.5XXA — Foreign body in anus and rectum, initial encounter
• T18.5XXD — Foreign body in anus and rectum, subsequent encounter
• T18.5XXS — Foreign body in anus and rectum, sequela
• T18.8 — Foreign body in other parts of alimentary tract
• T18.8XXA — Foreign body in other parts of alimentary tract, initial encounter
• T18.8XXD — Foreign body in other parts of alimentary tract, subsequent encounter
• T18.8XXS — Foreign body in other parts of alimentary tract, sequela
• T18.9 — Foreign body of alimentary tract, part unspecified
• T18.9XXA — Foreign body of alimentary tract, part unspecified, initial encounter

View all codes in the T18 family