ICD-10-CM · FY 2026 APRIL UPDATE

S66

Injury of muscle, fascia and tendon at wrist and hand level

Diagnosis reference

Nonbillable category

This entry is a category or subcategory. Choose the appropriate billable descendant based on the clinical documentation.

Effective periodOctober 1, 2026–September 30, 2027

SourceCMS ICD-10-CM order file

ClassificationDiagnosis · clinical modification

Related entries

Up to 30 descendants in this category

CODE	DESCRIPTION	TYPE
S66.0	Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level	Category
S66.00	Unspecified injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level	Category
S66.001	Unspecified injury of long flexor muscle, fascia and tendon of right thumb at wrist and hand level	Category
S66.001A	Unspecified injury of long flexor muscle, fascia and tendon of right thumb at wrist and hand level, initial encounter	Billable
S66.001D	Unspecified injury of long flexor muscle, fascia and tendon of right thumb at wrist and hand level, subsequent encounter	Billable
S66.001S	Unspecified injury of long flexor muscle, fascia and tendon of right thumb at wrist and hand level, sequela	Billable
S66.002	Unspecified injury of long flexor muscle, fascia and tendon of left thumb at wrist and hand level	Category
S66.002A	Unspecified injury of long flexor muscle, fascia and tendon of left thumb at wrist and hand level, initial encounter	Billable
S66.002D	Unspecified injury of long flexor muscle, fascia and tendon of left thumb at wrist and hand level, subsequent encounter	Billable
S66.002S	Unspecified injury of long flexor muscle, fascia and tendon of left thumb at wrist and hand level, sequela	Billable
S66.009	Unspecified injury of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand level	Category
S66.009A	Unspecified injury of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand level, initial encounter	Billable
S66.009D	Unspecified injury of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand level, subsequent encounter	Billable
S66.009S	Unspecified injury of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand level, sequela	Billable
S66.01	Strain of long flexor muscle, fascia and tendon of thumb at wrist and hand level	Category
S66.011	Strain of long flexor muscle, fascia and tendon of right thumb at wrist and hand level	Category
S66.011A	Strain of long flexor muscle, fascia and tendon of right thumb at wrist and hand level, initial encounter	Billable
S66.011D	Strain of long flexor muscle, fascia and tendon of right thumb at wrist and hand level, subsequent encounter	Billable
S66.011S	Strain of long flexor muscle, fascia and tendon of right thumb at wrist and hand level, sequela	Billable
S66.012	Strain of long flexor muscle, fascia and tendon of left thumb at wrist and hand level	Category
S66.012A	Strain of long flexor muscle, fascia and tendon of left thumb at wrist and hand level, initial encounter	Billable
S66.012D	Strain of long flexor muscle, fascia and tendon of left thumb at wrist and hand level, subsequent encounter	Billable
S66.012S	Strain of long flexor muscle, fascia and tendon of left thumb at wrist and hand level, sequela	Billable
S66.019	Strain of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand level	Category
S66.019A	Strain of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand level, initial encounter	Billable
S66.019D	Strain of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand level, subsequent encounter	Billable
S66.019S	Strain of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand level, sequela	Billable
S66.02	Laceration of long flexor muscle, fascia and tendon of thumb at wrist and hand level	Category
S66.021	Laceration of long flexor muscle, fascia and tendon of right thumb at wrist and hand level	Category
S66.021A	Laceration of long flexor muscle, fascia and tendon of right thumb at wrist and hand level, initial encounter	Billable

Use the complete reference

This reference does not reproduce the full tabular hierarchy, inclusion notes, Excludes1/2 notes, sequencing instructions, or seventh-character rules. Review the official tables and coding guidelines.

Open official CMS files

ICD-10-CM codes describe diagnoses. They do not have an independent Medicare PFS reimbursement amount, and billability alone does not establish coverage.