2024 ICD-10-CM Diagnosis Code S66.1

Injury of flexor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

ICD-10-CM Code:
S66.1
ICD-10 Code for:
Inj flexor musc/fasc/tend and unsp finger at wrs/hnd lv
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Injury, poisoning and certain other consequences of external causes
    (S00–T88)
    • Injuries to the wrist, hand and fingers
      (S60-S69)
      • Injury of muscle, fascia and tendon at wrist and hand level
        (S66)

S66.1 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of injury of flexor muscle, fascia and tendon of other and unspecified finger at wrist and hand level. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Unspecified diagnosis codes like S66.1 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Specific Coding Applicable to Inj flexor musc/fasc/tend and unsp finger at wrs/hnd lv

Non-specific codes like S66.1 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for inj flexor musc/fasc/tend and unsp finger at wrs/hnd lv:

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

  • S66.100 for Unspecified injury of flexor muscle, fascia and tendon of right index finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.100A for initial encounter - BILLABLE CODE

  • Use S66.100D for subsequent encounter - BILLABLE CODE

  • Use S66.100S for sequela - BILLABLE CODE

  • S66.101 for Unspecified injury of flexor muscle, fascia and tendon of left index finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.101A for initial encounter - BILLABLE CODE

  • Use S66.101D for subsequent encounter - BILLABLE CODE

  • Use S66.101S for sequela - BILLABLE CODE

  • S66.102 for Unspecified injury of flexor muscle, fascia and tendon of right middle finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.102A for initial encounter - BILLABLE CODE

  • Use S66.102D for subsequent encounter - BILLABLE CODE

  • Use S66.102S for sequela - BILLABLE CODE

  • S66.103 for Unspecified injury of flexor muscle, fascia and tendon of left middle finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.103A for initial encounter - BILLABLE CODE

  • Use S66.103D for subsequent encounter - BILLABLE CODE

  • Use S66.103S for sequela - BILLABLE CODE

  • S66.104 for Unspecified injury of flexor muscle, fascia and tendon of right ring finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.104A for initial encounter - BILLABLE CODE

  • Use S66.104D for subsequent encounter - BILLABLE CODE

  • Use S66.104S for sequela - BILLABLE CODE

  • S66.105 for Unspecified injury of flexor muscle, fascia and tendon of left ring finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.105A for initial encounter - BILLABLE CODE

  • Use S66.105D for subsequent encounter - BILLABLE CODE

  • Use S66.105S for sequela - BILLABLE CODE

  • S66.106 for Unspecified injury of flexor muscle, fascia and tendon of right little finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.106A for initial encounter - BILLABLE CODE

  • Use S66.106D for subsequent encounter - BILLABLE CODE

  • Use S66.106S for sequela - BILLABLE CODE

  • S66.107 for Unspecified injury of flexor muscle, fascia and tendon of left little finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.107A for initial encounter - BILLABLE CODE

  • Use S66.107D for subsequent encounter - BILLABLE CODE

  • Use S66.107S for sequela - BILLABLE CODE

  • S66.108 for Unspecified injury of flexor muscle, fascia and tendon of other finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.108A for initial encounter - BILLABLE CODE

  • Use S66.108D for subsequent encounter - BILLABLE CODE

  • Use S66.108S for sequela - BILLABLE CODE

  • S66.109 for Unspecified injury of flexor muscle, fascia and tendon of unspecified finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.109A for initial encounter - BILLABLE CODE

  • Use S66.109D for subsequent encounter - BILLABLE CODE

  • Use S66.109S for sequela - BILLABLE CODE

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

  • S66.110 for Strain of flexor muscle, fascia and tendon of right index finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.110A for initial encounter - BILLABLE CODE

  • Use S66.110D for subsequent encounter - BILLABLE CODE

  • Use S66.110S for sequela - BILLABLE CODE

  • S66.111 for Strain of flexor muscle, fascia and tendon of left index finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.111A for initial encounter - BILLABLE CODE

  • Use S66.111D for subsequent encounter - BILLABLE CODE

  • Use S66.111S for sequela - BILLABLE CODE

  • S66.112 for Strain of flexor muscle, fascia and tendon of right middle finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.112A for initial encounter - BILLABLE CODE

  • Use S66.112D for subsequent encounter - BILLABLE CODE

  • Use S66.112S for sequela - BILLABLE CODE

  • S66.113 for Strain of flexor muscle, fascia and tendon of left middle finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.113A for initial encounter - BILLABLE CODE

  • Use S66.113D for subsequent encounter - BILLABLE CODE

  • Use S66.113S for sequela - BILLABLE CODE

  • S66.114 for Strain of flexor muscle, fascia and tendon of right ring finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.114A for initial encounter - BILLABLE CODE

  • Use S66.114D for subsequent encounter - BILLABLE CODE

  • Use S66.114S for sequela - BILLABLE CODE

  • S66.115 for Strain of flexor muscle, fascia and tendon of left ring finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.115A for initial encounter - BILLABLE CODE

  • Use S66.115D for subsequent encounter - BILLABLE CODE

  • Use S66.115S for sequela - BILLABLE CODE

  • S66.116 for Strain of flexor muscle, fascia and tendon of right little finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.116A for initial encounter - BILLABLE CODE

  • Use S66.116D for subsequent encounter - BILLABLE CODE

  • Use S66.116S for sequela - BILLABLE CODE

  • S66.117 for Strain of flexor muscle, fascia and tendon of left little finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.117A for initial encounter - BILLABLE CODE

  • Use S66.117D for subsequent encounter - BILLABLE CODE

  • Use S66.117S for sequela - BILLABLE CODE

  • S66.118 for Strain of flexor muscle, fascia and tendon of other finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.118A for initial encounter - BILLABLE CODE

  • Use S66.118D for subsequent encounter - BILLABLE CODE

  • Use S66.118S for sequela - BILLABLE CODE

  • S66.119 for Strain of flexor muscle, fascia and tendon of unspecified finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.119A for initial encounter - BILLABLE CODE

  • Use S66.119D for subsequent encounter - BILLABLE CODE

  • Use S66.119S for sequela - BILLABLE CODE

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

  • S66.120 for Laceration of flexor muscle, fascia and tendon of right index finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.120A for initial encounter - BILLABLE CODE

  • Use S66.120D for subsequent encounter - BILLABLE CODE

  • Use S66.120S for sequela - BILLABLE CODE

  • S66.121 for Laceration of flexor muscle, fascia and tendon of left index finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.121A for initial encounter - BILLABLE CODE

  • Use S66.121D for subsequent encounter - BILLABLE CODE

  • Use S66.121S for sequela - BILLABLE CODE

  • S66.122 for Laceration of flexor muscle, fascia and tendon of right middle finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.122A for initial encounter - BILLABLE CODE

  • Use S66.122D for subsequent encounter - BILLABLE CODE

  • Use S66.122S for sequela - BILLABLE CODE

  • S66.123 for Laceration of flexor muscle, fascia and tendon of left middle finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.123A for initial encounter - BILLABLE CODE

  • Use S66.123D for subsequent encounter - BILLABLE CODE

  • Use S66.123S for sequela - BILLABLE CODE

  • S66.124 for Laceration of flexor muscle, fascia and tendon of right ring finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.124A for initial encounter - BILLABLE CODE

  • Use S66.124D for subsequent encounter - BILLABLE CODE

  • Use S66.124S for sequela - BILLABLE CODE

  • S66.125 for Laceration of flexor muscle, fascia and tendon of left ring finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.125A for initial encounter - BILLABLE CODE

  • Use S66.125D for subsequent encounter - BILLABLE CODE

  • Use S66.125S for sequela - BILLABLE CODE

  • S66.126 for Laceration of flexor muscle, fascia and tendon of right little finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.126A for initial encounter - BILLABLE CODE

  • Use S66.126D for subsequent encounter - BILLABLE CODE

  • Use S66.126S for sequela - BILLABLE CODE

  • S66.127 for Laceration of flexor muscle, fascia and tendon of left little finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.127A for initial encounter - BILLABLE CODE

  • Use S66.127D for subsequent encounter - BILLABLE CODE

  • Use S66.127S for sequela - BILLABLE CODE

  • S66.128 for Laceration of flexor muscle, fascia and tendon of other finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.128A for initial encounter - BILLABLE CODE

  • Use S66.128D for subsequent encounter - BILLABLE CODE

  • Use S66.128S for sequela - BILLABLE CODE

  • S66.129 for Laceration of flexor muscle, fascia and tendon of unspecified finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.129A for initial encounter - BILLABLE CODE

  • Use S66.129D for subsequent encounter - BILLABLE CODE

  • Use S66.129S for sequela - BILLABLE CODE

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

  • S66.190 for Other injury of flexor muscle, fascia and tendon of right index finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.190A for initial encounter - BILLABLE CODE

  • Use S66.190D for subsequent encounter - BILLABLE CODE

  • Use S66.190S for sequela - BILLABLE CODE

  • S66.191 for Other injury of flexor muscle, fascia and tendon of left index finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.191A for initial encounter - BILLABLE CODE

  • Use S66.191D for subsequent encounter - BILLABLE CODE

  • Use S66.191S for sequela - BILLABLE CODE

  • S66.192 for Other injury of flexor muscle, fascia and tendon of right middle finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.192A for initial encounter - BILLABLE CODE

  • Use S66.192D for subsequent encounter - BILLABLE CODE

  • Use S66.192S for sequela - BILLABLE CODE

  • S66.193 for Other injury of flexor muscle, fascia and tendon of left middle finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.193A for initial encounter - BILLABLE CODE

  • Use S66.193D for subsequent encounter - BILLABLE CODE

  • Use S66.193S for sequela - BILLABLE CODE

  • S66.194 for Other injury of flexor muscle, fascia and tendon of right ring finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.194A for initial encounter - BILLABLE CODE

  • Use S66.194D for subsequent encounter - BILLABLE CODE

  • Use S66.194S for sequela - BILLABLE CODE

  • S66.195 for Other injury of flexor muscle, fascia and tendon of left ring finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.195A for initial encounter - BILLABLE CODE

  • Use S66.195D for subsequent encounter - BILLABLE CODE

  • Use S66.195S for sequela - BILLABLE CODE

  • S66.196 for Other injury of flexor muscle, fascia and tendon of right little finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.196A for initial encounter - BILLABLE CODE

  • Use S66.196D for subsequent encounter - BILLABLE CODE

  • Use S66.196S for sequela - BILLABLE CODE

  • S66.197 for Other injury of flexor muscle, fascia and tendon of left little finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.197A for initial encounter - BILLABLE CODE

  • Use S66.197D for subsequent encounter - BILLABLE CODE

  • Use S66.197S for sequela - BILLABLE CODE

  • S66.198 for Other injury of flexor muscle, fascia and tendon of other finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.198A for initial encounter - BILLABLE CODE

  • Use S66.198D for subsequent encounter - BILLABLE CODE

  • Use S66.198S for sequela - BILLABLE CODE

  • S66.199 for Other injury of flexor muscle, fascia and tendon of unspecified finger at wrist and hand level - NON-BILLABLE CODE

  • Use S66.199A for initial encounter - BILLABLE CODE

  • Use S66.199D for subsequent encounter - BILLABLE CODE

  • Use S66.199S for sequela - BILLABLE CODE

Coding Guidelines

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 aplicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Type 2 Excludes

Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
  • Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level S66.0

Patient Education


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.

Hand problems include :

  • Carpal tunnel syndrome - compression of a nerve as it goes through the wrist, often making your fingers feel numb
  • Injuries that result in fractures (broken bones), ruptured ligaments and dislocations
  • Osteoarthritis - wear-and-tear arthritis, which can also cause deformity
  • Tendinitis - irritation of the tendons
  • Disorders and injuries of your fingers and thumb

[Learn More in MedlinePlus]

Wrist Injuries and Disorders

Your wrist connects your hand to your forearm. It is not one big joint; it has several small joints. This makes it flexible and allows you to move your hand in different ways. The wrist has two big forearm bones and eight small bones known as carpals. It also has tendons and ligaments, which are connective tissues. Tendons connect muscles to bones. Ligaments connect bones to each other.

What are the types of wrist injuries and disorders?

Some of the more common types of wrist injuries and disorders are:

  • Carpal tunnel syndrome, which happens when a nerve that runs from your forearm into your palm becomes squeezed at the wrist
  • Ganglion cysts, which are noncancerous lumps or masses
  • Gout, which is a form of arthritis caused by a buildup of uric acid in your joints
  • Fractures (broken bones)
  • Osteoarthritis, the most common type of arthritis. It is caused by wear and tear of the joints.
  • Sprains and strains, which are injuries to ligaments and injuries to muscles or tendons
  • Tendinitis, inflammation of a tendon, usually due to overuse

Who is at risk for wrist injuries and disorders?

Certain things can put you at higher risk of having a wrist problem, including:

  • Doing sports, which can put you at risk for injuries and puts stress on your wrist. For example, you may fall on your outstretched hand when you are skating or snowboarding. Your wrist could be injured while doing contact sports. And other sports such as gymnastics and basketball can strain your wrists.
  • Doing repetitive wrist motions, such as typing on a keyboard, working on an assembly line, or using power tools.
  • Having certain diseases. For example, rheumatoid arthritis can cause wrist pain.

What are the symptoms of wrist injuries and disorders?

The symptoms of a wrist problem can vary, depending on the problem. A common symptom is wrist pain. Some other possible symptoms include swelling, a decrease in wrist strength, and sudden numbness or tingling.

How are wrist injuries and disorders diagnosed?

Your health care provider may use many tools to make a diagnosis:

  • A medical history, which includes asking about your symptoms
  • A physical exam, including checking your wrist strength and range of motion
  • An x-ray or other imaging test
  • Blood tests

What are the treatments for wrist injuries and disorders?

Treatments for wrist pain depends on the type of injury or disorder. They may include:

  • Resting your wrist
  • Wearing a wrist brace or cast
  • Pain relievers
  • Cortisone shots
  • Physical therapy
  • Surgery

Can wrist injuries and disorders be prevented?

To try to prevent wrist problems, you can:

  • Use wrist guards, when doing sports that put you at risk for wrist injuries
  • In the workplace, perform stretching exercises and take frequent rest breaks. You should also pay attention to ergonomics to make sure that you are using the proper wrist position while working.
  • Make sure that you get enough calcium and vitamin D to keep your bones strong

[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.