Billable / Specific Code
ICD-10-CM D04.121 is the diagnosis code for Carcinoma in situ of skin of left upper eyelid, including canthus. This code falls under the section "In situ neoplasms" within Chapter 2 — Neoplasms (C00-D49). 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 D04.121 sits in the ICD-10-CM classification helps ensure proper coding:
Yes, D04.121 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
D04.121 is the ICD-10-CM diagnosis code for "Carcinoma in situ of skin of left upper eyelid, including canthus". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of D04.121 is D04.12 ("Carcinoma in situ of skin of left eyelid, including canthus"). D04.121 provides a more specific classification within this category.
D04.121 is located in Section D00-D09 — "In situ neoplasms" within Chapter 2 of the ICD-10-CM Tabular List.
Use D04.121 when the patients documented diagnosis matches "Carcinoma in situ of skin of left upper eyelid, including canthus" 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 Carcinoma in situ of skin of left upper eyelid, including canthus is D04.121.
Yes, D04.121 can be used as a primary diagnosis code since it is billable and specific.
D04.121 is in Chapter 2 of the ICD-10-CM Tabular List.
Yes, D04.121 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.