ICD-10-CM 2027 diagnosis code
S66.41Strain of intrinsic muscle, fascia and tendon of thumb at wrist and hand level
S66.41 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it and add the required 7th character.Short description: Strain of intrinsic musc/fasc/tend thumb 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 S66.41
S66.41 is the ICD-10-CM diagnosis code for strain of intrinsic muscle, fascia and tendon of thumb 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 3 subcodes must be used instead.
Within S66.4 (injury of intrinsic muscle, fascia and tendon of thumb at wrist and hand level), S66.41 is specifically for strain of intrinsic muscle, fascia and tendon of thumb at wrist and hand level. Related codes cover unspecified injury of intrinsic muscle, fascia and tendon of thumb at wrist and hand level (S66.40), laceration of intrinsic muscle, fascia and tendon of thumb at wrist and hand level (S66.42) and other specified injury of intrinsic muscle, fascia and tendon of thumb at wrist and hand level (S66.49).
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.
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
- S66.411Strain of intrinsic muscle, fascia and tendon of right thumb at wrist and hand level
- S66.412Strain of intrinsic muscle, fascia and tendon of left thumb at wrist and hand level
- S66.419Strain of intrinsic muscle, fascia and tendon of unspecified thumb at wrist and hand level
- Ainitial encounter
- Dsubsequent encounter
- Ssequela
Notes that apply from higher levels
Instructions written at a parent level also apply to S66.41.
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.
Alphabetic index entries
1 entriesTerms in the official ICD-10-CM index that lead to S66.41.
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 S66.41
Is S66.41 billable?
- No. S66.41 is a header code. Report one of its more specific subcodes instead.