ICD-10 Code D03.5 – Melanoma in situ of trunk (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D03.5 – Melanoma in situ of trunk
What it is
D03.5 identifies melanoma in situ on the trunk, meaning malignant melanocytic cells are confined to the epidermis and have not invaded deeper tissue. Use it when the lesion is documented on the trunk, including the chest, back, abdomen, or flanks.
Clinical signs
Clinical features vary; refer to documentation. Typical notes describe a suspicious pigmented lesion with asymmetry, border irregularity, color variation, or change over time, confirmed by pathology as in situ melanoma.
When to use this code
Use D03.5 when the provider documents melanoma in situ and specifies the trunk as the site. It also fits pathology-confirmed lesions described as noninvasive melanoma limited to the trunk. If the anatomic site is unclear, check documentation before coding.
Do not use for
Do not use this code for invasive melanoma, benign nevi, or unspecified skin lesions. It is also wrong when the lesion is on another body site; choose the correct site-specific code instead.
Coding tip
Verify both the in situ diagnosis and the trunk location in the pathology or provider note before assigning D03.5.