S66.421 – Laceration of intrinsic muscle, fascia and tendon of right thumb at wrist and hand level
ICD-10-CM 2027 diagnosis code · Injuries to the wrist, hand and fingers
- Code
S66.421(claims format:S66421)- Description
- Laceration of intrinsic muscle, fascia and tendon of right thumb at wrist and hand level
- Short description
- Lacerat intrinsic musc/fasc/tend right thumb at wrs/hnd lv
- Billable
- No – use a more specific code below
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 19. Injury, poisoning and certain other consequences of external causes (S00-T88)
- Block
- S60-S69 Injuries to the wrist, hand and fingers
- Parent codes
- S66 › S66.4 › S66.42
Billable codes under S66.421
S66.421 is a header code and cannot be used on claims. Choose the most specific code:
- S66.421A – Laceration of intrinsic muscle, fascia and tendon of right thumb at wrist and hand level, initial encounterBillable
- S66.421D – Laceration of intrinsic muscle, fascia and tendon of right thumb at wrist and hand level, subsequent encounterBillable
- S66.421S – Laceration of intrinsic muscle, fascia and tendon of right thumb at wrist and hand level, sequelaBillable
7th character values
Codes in this category need a 7th character to describe the encounter or episode of care.
| Character | Meaning |
|---|---|
A | initial encounter |
D | subsequent encounter |
S | sequela |
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
S66 – Injury of muscle, fascia and tendon at wrist and hand level
- sprain of joints and ligaments of wrist and hand (S63.-)
- any associated open wound (S61.-)
- The appropriate 7th character is to be added to each code from category S66
Block S60-S69
Related codes in S66.42
Frequently asked questions
What is ICD-10 code S66.421?
S66.421 is the ICD-10-CM code for laceration of intrinsic muscle, fascia and tendon of right thumb at wrist and hand level, in the block S60-S69 (Injuries to the wrist, hand and fingers).
Is S66.421 a billable code?
No. S66.421 is a header code with more specific child codes; report one of the billable codes listed above.
What category does S66.421 belong to?
It belongs to category S66 – Injury of muscle, fascia and tendon at wrist and hand level.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.