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

ICD-10-CM 2027 diagnosis code · Injuries to the wrist, hand and fingers

Non-billable header

ICD-10-CM code S66.49

Code: S66.49 (claims format: S6649)
Description: Other specified injury of intrinsic muscle, fascia and tendon of thumb at wrist and hand level
Short description: Inj intrinsic musc/fasc/tend thumb at wrist and hand level
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

Billable codes under S66.49

S66.49 is a header code and cannot be used on claims. Choose the most specific code:

S66.491 – Other specified injury of intrinsic muscle, fascia and tendon of right thumb at wrist and hand levelHeader (more codes below)
S66.492 – Other specified injury of intrinsic muscle, fascia and tendon of left thumb at wrist and hand levelHeader (more codes below)
S66.499 – Other specified injury of intrinsic muscle, fascia and tendon of unspecified thumb at wrist and hand levelHeader (more codes below)

7th character values

Codes in this category need a 7th character to describe the encounter or episode of care (use placeholder X for empty positions).

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

Excludes2 (not included here):

sprain of joints and ligaments of wrist and hand (S63.-)

Code also:

any associated open wound (S61.-)

7th character note:

The appropriate 7th character is to be added to each code from category S66

Block S60-S69

Excludes2 (not included here):

burns and corrosions (T20-T32)
frostbite (T33-T34)
insect bite or sting, venomous (T63.4)

Index terms for S66.49

Entries in the ICD-10-CM alphabetic index that lead to this code:

Injury, muscle, thumb, intrinsic, specified type NEC

Related codes in S66.4

Frequently asked questions

What is ICD-10 code S66.49?

S66.49 is the ICD-10-CM code for other specified injury of intrinsic muscle, fascia and tendon of thumb at wrist and hand level, in the block S60-S69 (Injuries to the wrist, hand and fingers).

Is S66.49 a billable code?

No. S66.49 is a header code with more specific child codes; report one of the billable codes listed above.

What category does S66.49 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.