Billable / Specific Code
ICD-10-CM S66.999 is the diagnosis code for Other injury of unspecified muscle, fascia and tendon at wrist and hand level, unspecified hand. 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 S66.999 sits in the ICD-10-CM classification helps ensure proper coding:
Yes, S66.999 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
S66.999 is the ICD-10-CM diagnosis code for "Other injury of unspecified muscle, fascia and tendon at wrist and hand level, unspecified hand". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of S66.999 is S66.99 ("Other injury of unspecified muscle, fascia and tendon at wrist and hand level"). S66.999 provides a more specific classification within this category.
S66.999 is located in Section S60-S69 — "Injuries to the wrist, hand and fingers" within Chapter 19 of the ICD-10-CM Tabular List.
Use S66.999 when the patients documented diagnosis matches "Other injury of unspecified muscle, fascia and tendon at wrist and hand level, unspecified hand" 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 unspecified muscle, fascia and tendon at wrist and hand level, unspecified hand is S66.999.
Yes, S66.999 can be used as a primary diagnosis code since it is billable and specific.
S66.999 is in Chapter 19 of the ICD-10-CM Tabular List.
Yes, S66.999 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.