ICD-10 Code D48.5 – Neoplasm of uncertain behavior of skin (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D48.5 – Neoplasm of uncertain behavior of skin
What it is
D48.5 identifies a skin growth whose behavior is uncertain, meaning the lesion cannot yet be classified as clearly benign or malignant. Use it when the record documents an indeterminate cutaneous neoplasm.
Clinical signs
Clinical features vary; refer to documentation. The lesion may be described as atypical, changing, or suspicious on exam, but pathology or follow-up may still be needed to determine its nature.
When to use this code
Use D48.5 when the provider documents a skin lesion or mass with uncertain behavior and does not assign a benign or malignant diagnosis. It is appropriate for lesions awaiting biopsy results or those reported as indeterminate after evaluation. Code only what the documentation supports.
Do not use for
Do not use this code for clearly benign skin lesions, confirmed skin cancers, or unspecified rashes. If the note gives a different final diagnosis, choose that code instead.
Coding tip
Verify the pathology, assessment, and final impression before selecting D48.5; if the behavior is not documented, check documentation.