2026 ICD-10-CM Diagnosis Code S36.021AMajor contusion of spleen, initial encounter
ICD-10-CM Codes›S00–T88›S30-S39›S36
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- 7th Character A — Initial Encounter
- Not Chronic
S36.021A is a billable ICD-10-CM diagnosis code for major contusion of spleen, 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 791, 793, 814 through 816, 963 through 965. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 169 closely related codes. 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
Spleen Diseases
Your spleen is an organ above your stomach and under your ribs on your left side. It is about as big as your fist. The spleen is part of your lymphatic system, which fights infection and keeps your body fluids in balance. It contains white blood cells that fight germs.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S36.021A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S36.021AOverview
What is the ICD-10 code for major contusion of spleen, initial encounter?
The ICD-10-CM code for major contusion of spleen, initial encounter is S36.021A (sometimes written as S36021A). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is S36.021A (Major contusion of spleen) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report major contusion of spleen, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S36.021A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for major contusion of spleen, such as an emergency visit or first evaluation.
What MS-DRG does S36.021A group to?
When major contusion of spleen, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 791, 793, 814, 815, 816, 963, 964, 965, with relative weights from 0.6320 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.
Is S36.021A a CC or MCC?
CMS lists S36.021A as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 169 closely related codes in its exclusion list.
