S56.3

⚠ Non-billable (Header)

Injury of extensor or abductor muscles, fascia and tendons of thumb at forearm level

Injury, poisoning and certain other consequences of external causes (S00-T88)

⚠️ This is a category header code — not billable. Use a more specific child code below.

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⚠️ Excludes2

inherited

Rules inherited from parent codes.

S56

• injury of muscle, fascia and tendon at or below wrist (S66.-)
• sprain of joints and ligaments of elbow (S53.4-)

Child Codes (4)

S56.30Unspecified injury of extensor or abductor muscles, fascia and tendons of thumb at forearm levelHeader S56.31Strain of extensor or abductor muscles, fascia and tendons of thumb at forearm levelHeader S56.32Laceration of extensor or abductor muscles, fascia and tendons of thumb at forearm levelHeader S56.39Other injury of extensor or abductor muscles, fascia and tendons of thumb at forearm levelHeader

Clinical Description

ICD-10-CM code S56.3 represents injury of extensor or abductor muscles, fascia and tendons of thumb at forearm level. This code falls under the Injury, poisoning and certain other consequences of external causes (S00-T88) classification. It is a non-billable category header code. A more specific child code from the list below must be used for billing and reimbursement purposes.

This is a 5-character code at the 4th level of specificity. There are 4 more specific child codes under S56.3.

Frequently Asked Questions

What is ICD-10 code S56.3?

ICD-10-CM code S56.3 is "Injury of extensor or abductor muscles, fascia and tendons of thumb at forearm level". It belongs to the category: Injury, poisoning and certain other consequences of external causes (S00-T88).

Is S56.3 a billable ICD-10 code?

No, S56.3 is a non-billable header code. A more specific child code must be used for billing.

Can S56.3 be coded with other codes?

S56.3 has 2 Excludes2 note(s). These conditions can be coded together if both are documented in the patient record.

Related Codes in S56

Other codes in the same category that may be relevant for differential coding:

S56.0Injury of flexor muscle, fascia and tendon of thumb at forearm level S56.1Injury of flexor muscle, fascia and tendon of other and unspecified finger at forearm level S56.2Injury of other flexor muscle, fascia and tendon at forearm level S56.4Injury of extensor muscle, fascia and tendon of other and unspecified finger at forearm level S56.5Injury of other extensor muscle, fascia and tendon at forearm level S56.8Injury of other muscles, fascia and tendons at forearm level S56.9Injury of unspecified muscles, fascia and tendons at forearm level

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Code Information

CodeS56.3

BillableNo — Header code

ParentS56

CategoryInjury, poisoning and certain other consequences of external causes (S00-T88)

Excludes10 rule(s)

Excludes22 note(s)

Child codes4

Data Source

CMS ICD-10-CM 2026 Tabular List

Updated October 1, 2025 (FY2026)