2026 ICD-10-CM Diagnosis Code S59.909AUnspecified injury of unspecified elbow, initial encounter
S59.909A is a billable ICD-10-CM diagnosis code for unspecified injury of unspecified 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 913 through 914, 963 through 965. Coders also document this condition as elbow joint effusion. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other unspecified injury.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Elbow joint effusion
- Injury of bursa of elbow
- Injury of elbow
- Traumatic effusion of joint of elbow
- Traumatic joint effusion
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Other and unspecified injuries of elbow and forearm (S59). 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
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S59.909A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S59.909AOverview
Is S59.909A (Unspecified injury of unspecified elbow) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified injury of unspecified elbow, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S59.909A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for unspecified injury of unspecified elbow, such as an emergency visit or first evaluation.
What MS-DRG does S59.909A group to?
When unspecified injury of unspecified elbow, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 913, 914, 963, 964, 965, with relative weights from 0.8855 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S59.909A?
Under the General Equivalence Mappings, unspecified injury of unspecified elbow, initial encounter converts to ICD-9-CM 959.3 (elb/forearm/wrst inj NOS). 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.
