Billable / Specific Code
ICD-10-CM S66.591 is the diagnosis code for Other injury of intrinsic muscle, fascia and tendon of left index finger at wrist and hand level. This code falls under the section "Injuries to the wrist, hand and fingers" within Chapter 19 — Injury, poisoning and certain other consequences of external causes (S00-T88). It is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
Always refer to the official ICD-10-CM Tabular List for complete coding guidelines. Ensure documentation supports the specificity of the code selected. When in doubt, consult a certified medical coder or the latest CMS guidelines.
Understanding where S66.591 sits in the ICD-10-CM classification helps ensure proper coding:
Yes, S66.591 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
S66.591 is the ICD-10-CM diagnosis code for "Other injury of intrinsic muscle, fascia and tendon of left index finger at wrist and hand level". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of S66.591 is S66.59 ("Other injury of intrinsic muscle, fascia and tendon of other and unspecified finger at wrist and hand level"). S66.591 provides a more specific classification within this category.
S66.591 is located in Section S60-S69 — "Injuries to the wrist, hand and fingers" within Chapter 19 of the ICD-10-CM Tabular List.
Use S66.591 when the patients documented diagnosis matches "Other injury of intrinsic muscle, fascia and tendon of left index finger at wrist and hand level" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Other injury of intrinsic muscle, fascia and tendon of left index finger at wrist and hand level is S66.591.
Yes, S66.591 can be used as a primary diagnosis code since it is billable and specific.
S66.591 is in Chapter 19 of the ICD-10-CM Tabular List.
Yes, S66.591 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.