ICD-10 Code D03 – Melanoma in situ (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D03 – Melanoma in situ
What it is
D03 identifies melanoma in situ, a melanoma confined to the epidermis without invasion into deeper skin layers. Use it when documentation states the lesion is in situ or noninvasive.
Clinical signs
Clinical features vary; refer to documentation. It is often described as a suspicious pigmented lesion with asymmetry, irregular borders, color variation, or change in size, but pathology confirmation is key.
When to use this code
Use D03 when the provider documents melanoma in situ, including a pathology report confirming noninvasive melanoma. Apply it for the specific anatomic site when available, and code additional details if the record supports them. Check documentation if the report is unclear about invasion.
Do not use for
Do not use D03 for invasive melanoma or for benign pigmented lesions such as nevi. If the pathology or note does not clearly state in situ disease, check documentation before assigning this code.
Coding tip
Code the highest level of specificity available, and confirm that “in situ” is explicitly documented before assigning D03.