ICD-10-CM · FY 2026 APRIL UPDATE

S66.10

Unspecified injury of flexor muscle, fascia and tendon of other and unspecified finger 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
S66.100	Unspecified injury of flexor muscle, fascia and tendon of right index finger at wrist and hand level	Category
S66.100A	Unspecified injury of flexor muscle, fascia and tendon of right index finger at wrist and hand level, initial encounter	Billable
S66.100D	Unspecified injury of flexor muscle, fascia and tendon of right index finger at wrist and hand level, subsequent encounter	Billable
S66.100S	Unspecified injury of flexor muscle, fascia and tendon of right index finger at wrist and hand level, sequela	Billable
S66.101	Unspecified injury of flexor muscle, fascia and tendon of left index finger at wrist and hand level	Category
S66.101A	Unspecified injury of flexor muscle, fascia and tendon of left index finger at wrist and hand level, initial encounter	Billable
S66.101D	Unspecified injury of flexor muscle, fascia and tendon of left index finger at wrist and hand level, subsequent encounter	Billable
S66.101S	Unspecified injury of flexor muscle, fascia and tendon of left index finger at wrist and hand level, sequela	Billable
S66.102	Unspecified injury of flexor muscle, fascia and tendon of right middle finger at wrist and hand level	Category
S66.102A	Unspecified injury of flexor muscle, fascia and tendon of right middle finger at wrist and hand level, initial encounter	Billable
S66.102D	Unspecified injury of flexor muscle, fascia and tendon of right middle finger at wrist and hand level, subsequent encounter	Billable
S66.102S	Unspecified injury of flexor muscle, fascia and tendon of right middle finger at wrist and hand level, sequela	Billable
S66.103	Unspecified injury of flexor muscle, fascia and tendon of left middle finger at wrist and hand level	Category
S66.103A	Unspecified injury of flexor muscle, fascia and tendon of left middle finger at wrist and hand level, initial encounter	Billable
S66.103D	Unspecified injury of flexor muscle, fascia and tendon of left middle finger at wrist and hand level, subsequent encounter	Billable
S66.103S	Unspecified injury of flexor muscle, fascia and tendon of left middle finger at wrist and hand level, sequela	Billable
S66.104	Unspecified injury of flexor muscle, fascia and tendon of right ring finger at wrist and hand level	Category
S66.104A	Unspecified injury of flexor muscle, fascia and tendon of right ring finger at wrist and hand level, initial encounter	Billable
S66.104D	Unspecified injury of flexor muscle, fascia and tendon of right ring finger at wrist and hand level, subsequent encounter	Billable
S66.104S	Unspecified injury of flexor muscle, fascia and tendon of right ring finger at wrist and hand level, sequela	Billable
S66.105	Unspecified injury of flexor muscle, fascia and tendon of left ring finger at wrist and hand level	Category
S66.105A	Unspecified injury of flexor muscle, fascia and tendon of left ring finger at wrist and hand level, initial encounter	Billable
S66.105D	Unspecified injury of flexor muscle, fascia and tendon of left ring finger at wrist and hand level, subsequent encounter	Billable
S66.105S	Unspecified injury of flexor muscle, fascia and tendon of left ring finger at wrist and hand level, sequela	Billable
S66.106	Unspecified injury of flexor muscle, fascia and tendon of right little finger at wrist and hand level	Category
S66.106A	Unspecified injury of flexor muscle, fascia and tendon of right little finger at wrist and hand level, initial encounter	Billable
S66.106D	Unspecified injury of flexor muscle, fascia and tendon of right little finger at wrist and hand level, subsequent encounter	Billable
S66.106S	Unspecified injury of flexor muscle, fascia and tendon of right little finger at wrist and hand level, sequela	Billable
S66.107	Unspecified injury of flexor muscle, fascia and tendon of left little finger at wrist and hand level	Category
S66.107A	Unspecified injury of flexor muscle, fascia and tendon of left little finger 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.