2026 ICD-10-CM Diagnosis Code S63.521ASprain of radiocarpal joint of right wrist, initial encounter

ICD-10-CM CodesS00–T88S60-S69S63

ICD-10-CM S63.521A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S63.521A is a billable ICD-10-CM diagnosis code for sprain of radiocarpal joint of right wrist, 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. Coders also document this condition as sprain of ligament of radiocarpal joint of right wrist. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sprains and strains, initial encounter.

Code Identity

ICD-10-CM Code
S63.521A
Billable Status
Yes — Valid for Submission
Code Describes
Sprain of radiocarpal joint of right wrist, initial encounter
Short Description
Sprain of radiocarpal joint of right wrist, init encntr
Parent Code
Sprain of radiocarpal joint of right wrist

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS60-S69Injuries to the wrist, hand and fingers
CategoryS63Dislocation and sprain of joints and ligaments at wrist and hand level
This CodeS63.521ASprain of radiocarpal joint of right wrist, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Sprain of ligament of radiocarpal joint of right wrist
  • Sprain of radiocarpal ligament
  • Sprain of right wrist

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments at wrist and hand level (S63). 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 INJ024
Sprains and strains, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Sprains and Strains

A sprain is a stretched or torn ligament. Ligaments are tissues that connect bones at a joint. Falling, twisting, or getting hit can all cause a sprain. Ankle and wrist sprains are common. Symptoms include pain, swelling, bruising, and being unable to move your joint. You might feel a pop or tear when the injury happens.

Read the full article at MedlinePlus

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

Convert S63.521A to ICD-9-CMHistory

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

ICD-9-CM
842.02 Sprain radiocarpal
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 S63.521AOverview

Is S63.521A (Sprain of radiocarpal joint of right wrist) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report sprain of radiocarpal joint of right wrist, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S63.521A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for sprain of radiocarpal joint of right wrist, such as an emergency visit or first evaluation.

What MS-DRG does S63.521A group to?

When sprain of radiocarpal joint of right wrist, 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 S63.521A?

Under the General Equivalence Mappings, sprain of radiocarpal joint of right wrist, initial encounter converts to ICD-9-CM 842.02 (sprain radiocarpal). 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.