Billable / Specific Code
ICD-10-CM T23.421 is the diagnosis code for Corrosion of unspecified degree of single right finger (nail) except thumb. This code falls under the section "Burns and corrosions of external body surface, specified by site" 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 T23.421 sits in the ICD-10-CM classification helps ensure proper coding:
Yes, T23.421 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
T23.421 is the ICD-10-CM diagnosis code for "Corrosion of unspecified degree of single right finger (nail) except thumb". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of T23.421 is T23.42 ("Corrosion of unspecified degree of single finger (nail) except thumb"). T23.421 provides a more specific classification within this category.
T23.421 is located in Section T20-T25 — "Burns and corrosions of external body surface, specified by site" within Chapter 19 of the ICD-10-CM Tabular List.
Use T23.421 when the patients documented diagnosis matches "Corrosion of unspecified degree of single right finger (nail) except thumb" 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 Corrosion of unspecified degree of single right finger (nail) except thumb is T23.421.
Yes, T23.421 can be used as a primary diagnosis code since it is billable and specific.
T23.421 is in Chapter 19 of the ICD-10-CM Tabular List.
Yes, T23.421 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.