2027 ICD-10-CM Diagnosis Code S64.10XAInjury of median nerve at wrist and hand level of unspecified arm, initial encounter

ICD-10-CM Codes›S00–T88›S60-S69›S64

ICD-10-CM S64.10XA
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S64.10XA is a billable ICD-10-CM diagnosis code for injury of median nerve at wrist and hand level of unspecified 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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 73 through 74, 963 through 965. Coders also document this condition as closed injury, median nerve, palmar sensory branch. 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
S64.10XA
Billable Status
Yes — Valid for Submission
Code Describes
Injury of median nerve at wrist and hand level of unspecified arm, initial encounter
Short Description
Injury of median nerve at wrs/hnd lv of unsp arm, init
Parent Code
S64.10
Injury of median nerve at wrist and hand level of unspecified 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 CodeS64.10XAInjury of median nerve at wrist and hand level of unspecified arm, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Closed injury, median nerve, palmar sensory branch
  • Injury of branch of median nerve
  • Injury of median nerve
  • Injury of median nerve in hand
  • Injury of median nerve in wrist
  • Injury of nerve at hand level
  • Injury of nerve at wrist level
  • Open injury, median nerve, palmar sensory branch

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 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to S64.10XA: its own notes plus those printed at S64, block S60-S69, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block S60-S69 Injuries to the wrist, hand and fingers applies to 5,118 codes
  • burns and corrosions (T20-T32)
  • frostbite (T33-T34)
  • insect bite or sting, venomous (T63.4)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From S64 Injury of nerves at wrist and hand level applies to 84 codes
  • any associated open wound (S61.-)

Notes

General instructions on how these codes are used.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From S64 Injury of nerves at wrist and hand level applies to 84 codes
  • The appropriate 7th character is to be added to each code from category S64
Values for category S64 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter this code
  • Dsubsequent encounter
  • Ssequela

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name S64.10XA, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming S64.10XA: its condition is not part of those codes, and both may be reported when the patient has both.

  • S54 Injury of nerves at forearm level
    injury of nerves at wrist and hand level (S64.-) names S64.-, which includes this code

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 S64.10XA to ICD-9-CMHistory

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

ICD-9-CM
955.1 Injury median nerve
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S64.10XAOverview

Is S64.10XA a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report injury of median nerve at wrist and hand level of unspecified arm, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in S64.10XA mean?

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

What MS-DRG does S64.10XA group to?

When injury of median nerve at wrist and hand level of unspecified arm, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 964, 965, 74, 73, 963, with relative weights from 1.0054 to 2.6361 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S64.10XA?

Under the General Equivalence Mappings, injury of median nerve at wrist and hand level of unspecified arm, initial encounter converts to ICD-9-CM 955.1 (injury median nerve). The mapping is approximate, so confirm the match fits the documentation.