S66.329A Laceration of extensor muscle, fascia and tendon of unspecified finger at wrist and hand level, initial encounter

Billable ICD-10-CM code, FY2026.

Built from S66.329 with 7th character A (initial encounter).

Applies from 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

7th character required

• A — initial encounter
• D — subsequent encounter
• S — sequela

Applies from S66.3 Injury of extensor muscle, fascia and tendon of other and unspecified finger at wrist and hand level

Excludes2 (not included here)

• Injury of extensor muscle, fascia and tendon of thumb at wrist and hand level (S66.2-)

Medicare Code Edits (MCE v43.1 (April 2026))

• Unspecified code (laterality): Unspecified codes for which a more specific code identifying laterality (right, left, bilateral) exists within the same code family.

Code annotations containing back-references to S66.329A

Back-references to S66

• Type 2 Excludes: S56 Injury of muscle, fascia and tendon at forearm level ("injury of muscle, fascia and tendon at or below wrist (S66.-)")
• Type 2 Excludes: S63 Dislocation and sprain of joints and ligaments at wrist and hand level ("strain of muscle, fascia and tendon of wrist and hand (S66.-)")

Diagnosis Index entries for S66.329A

• Injury › muscle (and fascia) (and tendon) › finger › extensor (forearm level) › hand level › laceration

Nearby codes

• S66.328 Laceration of extensor muscle, fascia and tendon of other finger at wrist and hand level
• S66.328A Laceration of extensor muscle, fascia and tendon of other finger at wrist and hand level, initial encounter
• S66.328D Laceration of extensor muscle, fascia and tendon of other finger at wrist and hand level, subsequent encounter
• S66.328S Laceration of extensor muscle, fascia and tendon of other finger at wrist and hand level, sequela
• S66.329 Laceration of extensor muscle, fascia and tendon of unspecified finger at wrist and hand level
• S66.329A Laceration of extensor muscle, fascia and tendon of unspecified finger at wrist and hand level, initial encounter (this code)
• S66.329D Laceration of extensor muscle, fascia and tendon of unspecified finger at wrist and hand level, subsequent encounter
• S66.329S Laceration of extensor muscle, fascia and tendon of unspecified finger at wrist and hand level, sequela
• S66.39 Other injury of extensor muscle, fascia and tendon of other and unspecified finger at wrist and hand level
• S66.390 Other injury of extensor muscle, fascia and tendon of right index finger at wrist and hand level
• S66.390A Other injury of extensor muscle, fascia and tendon of right index finger at wrist and hand level, initial encounter