CPT code 54100 denotes a diagnostic superficial skin biopsy of the penis, a focused ambulatory procedure used to obtain tissue for histologic diagnosis of penile mucocutaneous or dermal lesions. Nationally, accurate coding for this procedure is important for clinical documentation, appropriate claim adjudication, and tracking of dermatologic and urologic diagnostic services. The code applies primarily to outpatient settings such as dermatology or urology offices and ambulatory surgical centers and is commonly used when providers need definitive pathology for lesions suspicious for infection, inflammatory disease, or neoplasia.

Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of what CPT code 54100 represents, typical sites of service, and the clinical context in which the code is applied. The publication also summarizes how this code fits within common billing workflows, lists commonly encountered modifiers, and identifies areas where documentation typically influences payment and denial risk. Data not available in the input is noted where applicable. This resource is intended to clarify coding intent and support consistent use of CPT code 54100 across payers and clinical settings.