2026 ICD-10-CM Diagnosis Code S36.61XAPrimary blast injury of rectum, initial encounter

ICD-10-CM Codes›S00–T88›S30-S39›S36

ICD-10-CM S36.61XA
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S36.61XA is a billable ICD-10-CM diagnosis code for primary blast injury of rectum, 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 blast injury to intestines. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Internal organ injury, initial encounter.

Code Identity

ICD-10-CM Code
S36.61XA
Billable Status
Yes — Valid for Submission
Code Describes
Primary blast injury of rectum, initial encounter
Short Description
Primary blast injury of rectum, initial encounter
Same as the full description in the CMS dataset.
Parent Code
S36.61
Primary blast injury of rectum

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 CodeS36.61XAPrimary blast injury of rectum, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Blast injury to intestines
  • Primary blast injury of rectum

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

Rectal Disorders

The rectum is the lower part of your large intestine where your body stores stool. Problems with the rectum are common. They include hemorrhoids, abscesses, incontinence and cancer.

Read the full article at MedlinePlus

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

Convert S36.61XA to ICD-9-CMHistory

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

ICD-9-CM
863.45 Rectum injury-closed
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 S36.61XAOverview

Is S36.61XA (Primary blast injury of rectum) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report primary blast injury of rectum, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S36.61XA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for primary blast injury of rectum, such as an emergency visit or first evaluation.

What MS-DRG does S36.61XA group to?

When primary blast injury of rectum, 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 S36.61XA?

Under the General Equivalence Mappings, primary blast injury of rectum, initial encounter converts to ICD-9-CM 863.45 (rectum injury-closed). 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.