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T18.3XXA ICD-10-CM Code: Foreign body in small intestine, initial encounter

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

Inpatient Payment Groups (MS-DRG)

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43.0, Appendix B.

  • MS-DRG 393 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITH MCC (MDC 06)
  • MS-DRG 394 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITH CC (MDC 06)
  • MS-DRG 395 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITHOUT CC/MCC (MDC 06)

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.

Official Registry Overview & Definition

Foreign body in small intestine, initial encounter is a billable ICD-10-CM diagnosis code (T18.3A).

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T18.3XXA in the official ICD-10-CM tabular list.

Excludes2 — Not Included Here

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

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code, if known, for foreign body entering into or through a natural orifice (W44.-)

Frequently Compared Codes

The official Excludes notes on T18.3XXA name these codes. Each comparison page covers when the two can — or must not — be reported together.

Change history

No changes recorded for this code — unchanged since the FY2016 baseline of the change ledger.

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.

Relationships & Classification

Potential MS-DRG Relationships (FY2026)

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 3 MS-DRGs: DRG 393 (MDC 06), DRG 394 (MDC 06), DRG 395 (MDC 06).

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

Clinical classification (AHRQ CCSR):INJ020 — Effect of foreign body entering opening, initial encounter (default); EXT018 — External cause codes: other specified, classifiable and NEC; initial encounter; EXT020 — External cause codes: intent of injury, accidental/unintentional.

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

Contextual Map

Every relationship of T18.3XXA 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

  • S00-T88 — Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) (S00-T88) [Hierarchy]
  • T15-T19 — Effects of foreign body entering through natural orifice [Hierarchy]

Clinical classification (CCSR)

  • INJ020 — Effect of foreign body entering opening, initial encounter [CCSR]
  • EXT018 — External cause codes: other specified, classifiable and NEC; initial encounter [CCSR]
  • EXT020 — External cause codes: intent of injury, accidental/unintentional [CCSR]

Potential MS-DRG

  • DRG 393 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITH MCC [MS-DRG]: “OTHER DIGESTIVE SYSTEM DIAGNOSES WITH MCC (MDC 06)”
  • DRG 394 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITH CC [MS-DRG]: “OTHER DIGESTIVE SYSTEM DIAGNOSES WITH CC (MDC 06)”
  • DRG 395 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITHOUT CC/MCC [MS-DRG]: “OTHER DIGESTIVE SYSTEM DIAGNOSES WITHOUT CC/MCC (MDC 06)”

MDC crossing · procedures (5744)

  • MDC 06 — Diseases and Disorders of the Digestive System [MDC crossing]: “Diseases and Disorders of the Digestive 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.”
  • 008Q0ZZ — Division of Vagus Nerve, Open Approach [Same-MDC procedure]: “Division of Vagus Nerve, Open Approach — grouped in MDC 06, the procedure side of this code's crossing.” · check together
  • 008Q3ZZ — Division of Vagus Nerve, Percutaneous Approach [Same-MDC procedure]: “Division of Vagus Nerve, Percutaneous Approach — grouped in MDC 06, the procedure side of this code's crossing.” · check together
  • 008Q4ZZ — Division of Vagus Nerve, Percutaneous Endoscopic Approach [Same-MDC procedure]: “Division of Vagus Nerve, Percutaneous Endoscopic Approach — grouped in MDC 06, the procedure side of this code's crossing.” · check together
  • 02BP3ZZ — Excision of Pulmonary Trunk, Percutaneous Approach [Same-MDC procedure]: “Excision of Pulmonary Trunk, Percutaneous Approach — grouped in MDC 06, the procedure side of this code's crossing.” · check together
  • 02BQ3ZZ — Excision of Right Pulmonary Artery, Percutaneous Approach [Same-MDC procedure]: “Excision of Right Pulmonary Artery, Percutaneous Approach — grouped in MDC 06, the procedure side of this code's crossing.” · check together
  • and 5739 more

Nearest codes (40)

  • T18 — Foreign body in alimentary tract [Sibling]
  • T18.120 — Food in esophagus causing compression of trachea [Sibling]
  • T18.120A — Food in esophagus causing compression of trachea, initial encounter [Sibling]
  • T18.120D — Food in esophagus causing compression of trachea, subsequent encounter [Sibling]
  • T18.120S — Food in esophagus causing compression of trachea, sequela [Sibling]
  • T18.128 — Food in esophagus causing other injury [Sibling]
  • T18.128A — Food in esophagus causing other injury, initial encounter [Sibling]
  • T18.128D — Food in esophagus causing other injury, subsequent encounter [Sibling]
  • and 32 more

Frequently Asked Questions (FAQ) & Clinical Guidance

Does T18.3XXA require a 7th character?

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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T18.3XXA in its code family, with their registry titles.

  • T18.2 — Foreign body in stomach
  • T18.2XXA — Foreign body in stomach, initial encounter
  • T18.2XXD — Foreign body in stomach, subsequent encounter
  • T18.2XXS — Foreign body in stomach, sequela
  • T18.3 — Foreign body in small intestine
  • T18.3XXD — Foreign body in small intestine, subsequent encounter
  • T18.3XXS — Foreign body in small intestine, sequela
  • T18.4 — Foreign body in colon
  • T18.4XXA — Foreign body in colon, initial encounter
  • T18.4XXD — Foreign body in colon, subsequent encounter

View all codes in the T18 family