2026 ICD-10-CM Diagnosis Code S36.429AContusion of unspecified part of small intestine, initial encounter

ICD-10-CM Codes›S00–T88›S30-S39›S36

ICD-10-CM S36.429A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S36.429A is a billable ICD-10-CM diagnosis code for contusion of unspecified part of small intestine, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 393 through 395, 963 through 965. Coders also document this condition as contusion of small intestine. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Internal organ injury, initial encounter.

Code Identity

ICD-10-CM Code
S36.429A
Billable Status
Yes — Valid for Submission
Code Describes
Contusion of unspecified part of small intestine, initial encounter
Short Description
Contusion of unsp part of small intestine, init encntr
Parent Code
S36.429
Contusion of unspecified part of small intestine

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS30-S39Injuries to the abdomen, lower back, lumbar spine, pelvis and external genitals
CategoryS36Injury of intra-abdominal organs
This CodeS36.429AContusion of unspecified part of small intestine, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Contusion of small intestine

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Injury of intra-abdominal organs (S36). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ010
Internal organ injury, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Small Intestine Disorders

Your small intestine is the longest part of your digestive system - about twenty feet long! It connects your stomach to your large intestine (or colon) and folds many times to fit inside your abdomen. Your small intestine does most of the digesting of the foods you eat. It has three areas called the duodenum, the ileum, and the jejunum.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert S36.429A to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
863.20 Small intest inj NOS-cl
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S36.429AOverview

Is S36.429A (Contusion of unspecified part of small intestine) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report contusion of unspecified part of small intestine, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S36.429A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for contusion of unspecified part of small intestine, such as an emergency visit or first evaluation.

What MS-DRG does S36.429A group to?

When contusion of unspecified part of small intestine, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 393, 394, 395, 963, 964, 965, with relative weights from 0.6490 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S36.429A?

Under the General Equivalence Mappings, contusion of unspecified part of small intestine, initial encounter converts to ICD-9-CM 863.20 (small intest inj NOS-cl). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.