2026 ICD-10-CM Diagnosis Code S64.8X1AInjury of other nerves at wrist and hand level of right arm, initial encounter

ICD-10-CM Codes›S00–T88›S60-S69›S64

ICD-10-CM S64.8X1A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S64.8X1A is a billable ICD-10-CM diagnosis code for injury of other nerves at wrist and hand level of right arm, 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 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury to nerves, muscles and tendons, initial encounter.

Code Identity

ICD-10-CM Code
S64.8X1A
Billable Status
Yes — Valid for Submission
Code Describes
Injury of other nerves at wrist and hand level of right arm, initial encounter
Short Description
Injury of nerves at wrist and hand level of right arm, init
Parent Code
S64.8X1
Injury of other nerves at wrist and hand level of right arm

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS60-S69Injuries to the wrist, hand and fingers
CategoryS64Injury of nerves at wrist and hand level
This CodeS64.8X1AInjury of other nerves at wrist and hand level of right arm, initial encounter

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Injury of nerves at wrist and hand level (S64). 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 INJ025
Injury to nerves, muscles and tendons, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Hand Injuries and Disorders

No matter how old you are or what you do for a living, you are always using your hands. When there is something wrong with them, you may not be able to do your regular activities.

Read the full article at MedlinePlus

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

Convert S64.8X1A to ICD-9-CMHistory

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

ICD-9-CM
955.7 Inj nerve shldr/arm NEC
Approximate The match is approximate rather than exact.
ICD-9-CM
955.8 Inj mult nerve shldr/arm
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 S64.8X1AOverview

Is S64.8X1A (Injury of other nerves at wrist and hand level of right arm) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report injury of other nerves at wrist and hand level of right arm, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S64.8X1A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for injury of other nerves at wrist and hand level of right arm, such as an emergency visit or first evaluation.

What MS-DRG does S64.8X1A group to?

When injury of other nerves at wrist and hand level of right arm, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 963, 964, 965, with relative weights from 0.9405 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S64.8X1A?

Under the General Equivalence Mappings, injury of other nerves at wrist and hand level of right arm, initial encounter converts to ICD-9-CM 955.7 (inj nerve shldr/arm NEC) and 955.8 (inj mult nerve shldr/arm). 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.