2026 ICD-10-CM Diagnosis Code S53.421AUlnohumeral (joint) sprain of right elbow, initial encounter
S53.421A is a billable ICD-10-CM diagnosis code for ulnohumeral (joint) sprain of right elbow, 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 562 through 563, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sprains and strains, initial encounter.
Code Identity
Code Classification
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments of elbow (S53). 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
Elbow Injuries and Disorders
Your elbow joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the elbow joint move. When any of these structures is hurt or diseased, you have elbow problems.
Read the full article at MedlinePlus
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Convert S53.421A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S53.421AOverview
Is S53.421A (Ulnohumeral (joint) sprain of right elbow) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report ulnohumeral (joint) sprain of right elbow, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S53.421A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for ulnohumeral (joint) sprain of right elbow, such as an emergency visit or first evaluation.
What MS-DRG does S53.421A group to?
When ulnohumeral (joint) sprain of right elbow, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 562, 563, 963, 964, 965, with relative weights from 0.8955 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S53.421A?
Under the General Equivalence Mappings, ulnohumeral (joint) sprain of right elbow, initial encounter converts to ICD-9-CM 841.3 (sprain ulnohumeral). 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.
