2026 ICD-10-CM Diagnosis Code S36.518APrimary blast injury of other part of colon, initial encounter
S36.518A is a billable ICD-10-CM diagnosis code for primary blast injury of other part of colon, 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Internal organ injury, initial encounter.
Code Identity
Code Classification
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.
Patient EducationClinical
Colonic Diseases
Your colon, also known as the large intestine, is part of your digestive system. It's a long, hollow tube at the end of your digestive tract where your body makes and stores stool. Many disorders affect the colon's ability to work properly. Some of these include:
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S36.518A to ICD-9-CMHistory
Code HistoryHistory
Questions About S36.518AOverview
Is S36.518A (Primary blast injury of other part of colon) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report primary blast injury of other part of colon, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S36.518A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for primary blast injury of other part of colon, such as an emergency visit or first evaluation.
What MS-DRG does S36.518A group to?
When primary blast injury of other part of colon, 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 S36.518A?
Under the General Equivalence Mappings, primary blast injury of other part of colon, initial encounter converts to ICD-9-CM 863.46 (colon inj mult site-clos) and 863.49 (colon injury NEC-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.
