S66.309A Unspecified injury of extensor muscle, fascia and tendon of unspecified finger at wrist and hand level, initial encounter

Billable ICD-10-CM code, FY2026.

Built from S66.309 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-)

Code annotations containing back-references to S66.309A

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 S66.309A

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

Nearby codes

• S66.308 Unspecified injury of extensor muscle, fascia and tendon of other finger at wrist and hand level
• S66.308A Unspecified injury of extensor muscle, fascia and tendon of other finger at wrist and hand level, initial encounter
• S66.308D Unspecified injury of extensor muscle, fascia and tendon of other finger at wrist and hand level, subsequent encounter
• S66.308S Unspecified injury of extensor muscle, fascia and tendon of other finger at wrist and hand level, sequela
• S66.309 Unspecified injury of extensor muscle, fascia and tendon of unspecified finger at wrist and hand level
• S66.309A Unspecified injury of extensor muscle, fascia and tendon of unspecified finger at wrist and hand level, initial encounter (this code)
• S66.309D Unspecified injury of extensor muscle, fascia and tendon of unspecified finger at wrist and hand level, subsequent encounter
• S66.309S Unspecified injury of extensor muscle, fascia and tendon of unspecified finger at wrist and hand level, sequela
• S66.31 Strain of extensor muscle, fascia and tendon of other and unspecified finger at wrist and hand level
• S66.310 Strain of extensor muscle, fascia and tendon of right index finger at wrist and hand level
• S66.310A Strain of extensor muscle, fascia and tendon of right index finger at wrist and hand level, initial encounter