2027 ICD-10-CM Diagnosis Code S66Injury of muscle, fascia and tendon at wrist and hand level

ICD-10-CM Codes›S00–T88›S60-S69›S66

ICD-10-CM S66
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S66 is a non-billable ICD-10-CM category code for injury of muscle, fascia and tendon at wrist and hand level, so it cannot be submitted on claims. Use a more specific code from this category instead, such as S66.001A, S66.001D, S66.001S, and S66.002A.

Code Identity

ICD-10-CM Code
S66
Billable Status
No — Non-Billable Category
Code Describes
Injury of muscle, fascia and tendon at wrist and hand level
Short Description
Injury of muscle, fascia and tendon at wrist and hand level
Same as the full description in the CMS dataset.
Chapter
S60-S69
Injuries to the wrist, hand and fingers

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS60-S69Injuries to the wrist, hand and fingers
CategoryS66Injury of muscle, fascia and tendon at wrist and hand level
This CodeS66Injury of muscle, fascia and tendon at wrist and hand level

Specific Coding for Injury of muscle, fascia and tendon at wrist and hand levelOverview

Non-specific codes like S66 require more characters. Use one of these billable codes instead:

  • S66.0 for Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level

  • S66.00 for Unspecified injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level

  • S66.01 for Strain of long flexor muscle, fascia and tendon of thumb at wrist and hand level

  • S66.02 for Laceration of long flexor muscle, fascia and tendon of thumb at wrist and hand level

  • S66.09 for Other specified injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level

  • S66.1 for Injury of flexor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.10 for Unspecified injury of flexor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.11 for Strain of flexor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.12 for Laceration of flexor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.19 for Other injury of flexor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.2 for Injury of extensor muscle, fascia and tendon of thumb at wrist and hand level

  • S66.20 for Unspecified injury of extensor muscle, fascia and tendon of thumb at wrist and hand level

  • S66.21 for Strain of extensor muscle, fascia and tendon of thumb at wrist and hand level

  • S66.22 for Laceration of extensor muscle, fascia and tendon of thumb at wrist and hand level

  • S66.29 for Other specified injury of extensor muscle, fascia and tendon of thumb at wrist and hand level

  • S66.3 for Injury of extensor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.30 for Unspecified injury of extensor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.31 for Strain of extensor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.32 for Laceration of extensor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.39 for Other injury of extensor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.4 for Injury of intrinsic muscle, fascia and tendon of thumb at wrist and hand level

  • S66.40 for Unspecified injury of intrinsic muscle, fascia and tendon of thumb at wrist and hand level

  • S66.41 for Strain of intrinsic muscle, fascia and tendon of thumb at wrist and hand level

  • S66.42 for Laceration of intrinsic muscle, fascia and tendon of thumb at wrist and hand level

  • S66.49 for Other specified injury of intrinsic muscle, fascia and tendon of thumb at wrist and hand level

  • S66.5 for Injury of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.50 for Unspecified injury of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.51 for Strain of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.52 for Laceration of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.59 for Other injury of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level

  • S66.8 for Injury of other specified muscles, fascia and tendons at wrist and hand level

  • S66.80 for Unspecified injury of other specified muscles, fascia and tendons at wrist and hand level

  • S66.81 for Strain of other specified muscles, fascia and tendons at wrist and hand level

  • S66.82 for Laceration of other specified muscles, fascia and tendons at wrist and hand level

  • S66.89 for Other injury of other specified muscles, fascia and tendons at wrist and hand level

  • S66.9 for Injury of unspecified muscle, fascia and tendon at wrist and hand level

  • S66.90 for Unspecified injury of unspecified muscle, fascia and tendon at wrist and hand level

  • S66.91 for Strain of unspecified muscle, fascia and tendon at wrist and hand level

  • S66.92 for Laceration of unspecified muscle, fascia and tendon at wrist and hand level

  • S66.99 for Other injury of unspecified muscle, fascia and tendon at wrist and hand level

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Injury of muscle, fascia and tendon at wrist and hand level (S66). 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 S66: its own notes plus those printed at 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.

On S66 itself
  • sprain of joints and ligaments of wrist and hand (S63.-)
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.

  • 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.

  • The appropriate 7th character is to be added to each code from category S66
Values for category S66 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter
  • 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 S66, its category, or a range that includes it.

Excludes2 2

These codes carry an Excludes2 note naming S66: its condition is not part of those codes, and both may be reported when the patient has both.

  • S56 Injury of muscle, fascia and tendon at forearm level
    injury of muscle, fascia and tendon at or below wrist (S66.-)
  • S63 Dislocation and sprain of joints and ligaments at wrist and hand level
    strain of muscle, fascia and tendon of wrist and hand (S66.-)

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.

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 S66Overview

What is the ICD-10 code for injury of muscle, fascia and tendon at wrist and hand level?

S66 is the ICD-10-CM category for injury of muscle, fascia and tendon at wrist and hand level, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is S66 (Injury of muscle, fascia and tendon at wrist and hand level) a billable code?

No. This is a category header that groups the codes for injury of muscle, fascia and tendon at wrist and hand level, and headers cannot be submitted on claims. Claims for injury of muscle, fascia and tendon at wrist and hand level need a more specific code from this category, such as S66.001A, S66.001D, and S66.001S.