ICD-10-CM 2027 diagnosis code
S66.5Injury of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level
S66.5 is a header code, so it can't be reported by itself. Choose one of the 4 more specific codes beneath it and add the required 7th character.Short description: Inj intrinsic musc/fasc/tend and unsp finger at wrs/hnd lv
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About S66.5
S66.5 is the ICD-10-CM diagnosis code for injury of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level. It belongs to category S66 (injury of muscle, fascia and tendon at wrist and hand level), block S60-S69 (injuries to the wrist, hand and fingers) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 4 subcodes must be used instead.
Within S66, choose S66.5 (intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level) only when documentation doesn't support a more specific option: long flexor muscle, fascia and tendon of thumb at wrist and hand level (S66.0), flexor muscle, fascia and tendon of other and unspecified finger at wrist and hand level (S66.1), extensor muscle, fascia and tendon of thumb at wrist and hand level (S66.2), extensor muscle, fascia and tendon of other and unspecified finger at wrist and hand level (S66.3), intrinsic muscle, fascia and tendon of thumb at wrist and hand level (S66.4), other specified muscles, fascia and tendons at wrist and hand level (S66.8) and unspecified muscle, fascia and tendon at wrist and hand level (S66.9).
Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.
The conditions in its Excludes2 note aren't part of S66.5, but may be coded alongside it if the patient has both: injury of intrinsic muscle, fascia and tendon of thumb at wrist and hand level (S66.4-).
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
7th character
The appropriate 7th character is to be added to each code from category S66
- S66.50Unspecified injury of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level
- S66.500Unspecified injury of intrinsic muscle, fascia and tendon of right index finger at wrist and hand level
- S66.501Unspecified injury of intrinsic muscle, fascia and tendon of left index finger at wrist and hand level
- S66.502Unspecified injury of intrinsic muscle, fascia and tendon of right middle finger at wrist and hand level
- S66.503Unspecified injury of intrinsic muscle, fascia and tendon of left middle finger at wrist and hand level
- S66.504Unspecified injury of intrinsic muscle, fascia and tendon of right ring finger at wrist and hand level
- S66.505Unspecified injury of intrinsic muscle, fascia and tendon of left ring finger at wrist and hand level
- S66.506Unspecified injury of intrinsic muscle, fascia and tendon of right little finger at wrist and hand level
- S66.507Unspecified injury of intrinsic muscle, fascia and tendon of left little finger at wrist and hand level
- S66.508Unspecified injury of intrinsic muscle, fascia and tendon of other finger at wrist and hand level
- S66.509Unspecified injury of intrinsic muscle, fascia and tendon of unspecified finger at wrist and hand level
- S66.51Strain of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level
- S66.510Strain of intrinsic muscle, fascia and tendon of right index finger at wrist and hand level
- S66.511Strain of intrinsic muscle, fascia and tendon of left index finger at wrist and hand level
- S66.512Strain of intrinsic muscle, fascia and tendon of right middle finger at wrist and hand level
- S66.513Strain of intrinsic muscle, fascia and tendon of left middle finger at wrist and hand level
- S66.514Strain of intrinsic muscle, fascia and tendon of right ring finger at wrist and hand level
- S66.515Strain of intrinsic muscle, fascia and tendon of left ring finger at wrist and hand level
- S66.516Strain of intrinsic muscle, fascia and tendon of right little finger at wrist and hand level
- S66.517Strain of intrinsic muscle, fascia and tendon of left little finger at wrist and hand level
- S66.518Strain of intrinsic muscle, fascia and tendon of other finger at wrist and hand level
- S66.519Strain of intrinsic muscle, fascia and tendon of unspecified finger at wrist and hand level
- S66.52Laceration of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level
- S66.520Laceration of intrinsic muscle, fascia and tendon of right index finger at wrist and hand level
- S66.521Laceration of intrinsic muscle, fascia and tendon of left index finger at wrist and hand level
- S66.522Laceration of intrinsic muscle, fascia and tendon of right middle finger at wrist and hand level
- S66.523Laceration of intrinsic muscle, fascia and tendon of left middle finger at wrist and hand level
- S66.524Laceration of intrinsic muscle, fascia and tendon of right ring finger at wrist and hand level
- S66.525Laceration of intrinsic muscle, fascia and tendon of left ring finger at wrist and hand level
- S66.526Laceration of intrinsic muscle, fascia and tendon of right little finger at wrist and hand level
- S66.527Laceration of intrinsic muscle, fascia and tendon of left little finger at wrist and hand level
- S66.528Laceration of intrinsic muscle, fascia and tendon of other finger at wrist and hand level
- S66.529Laceration of intrinsic muscle, fascia and tendon of unspecified finger at wrist and hand level
- S66.59Other injury of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level
- S66.590Other injury of intrinsic muscle, fascia and tendon of right index finger at wrist and hand level
- S66.591Other injury of intrinsic muscle, fascia and tendon of left index finger at wrist and hand level
- S66.592Other injury of intrinsic muscle, fascia and tendon of right middle finger at wrist and hand level
- S66.593Other injury of intrinsic muscle, fascia and tendon of left middle finger at wrist and hand level
- S66.594Other injury of intrinsic muscle, fascia and tendon of right ring finger at wrist and hand level
- S66.595Other injury of intrinsic muscle, fascia and tendon of left ring finger at wrist and hand level
- S66.596Other injury of intrinsic muscle, fascia and tendon of right little finger at wrist and hand level
- S66.597Other injury of intrinsic muscle, fascia and tendon of left little finger at wrist and hand level
- S66.598Other injury of intrinsic muscle, fascia and tendon of other finger at wrist and hand level
- S66.599Other injury of intrinsic muscle, fascia and tendon of unspecified finger at wrist and hand level
- Ainitial encounter
- Dsubsequent encounter
- Ssequela
Coding notes
- injury of intrinsic muscle, fascia and tendon of thumb at wrist and hand level (S66.4-)
Notes that apply from higher levels
Instructions written at a parent level also apply to S66.5.
Broader instructions also apply from S60-S69 Injuries to the wrist, hand and fingers and Chapter 19: Injury, poisoning and certain other consequences of external causes.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about S66.5
Is S66.5 billable?
- No. S66.5 is a header code. Report one of its more specific subcodes instead.