CPT code 45100 represents an anal approach biopsy of the anorectal wall with submission of tissue for pathologic examination. As a focused diagnostic surgical procedure, it is used to obtain tissue samples when visual inspection, endoscopy, or imaging suggests pathology requiring histologic confirmation. Nationally, accurate coding of this procedure affects procedure utilization reporting, facility and physician reimbursement, and tracking of anorectal disease diagnoses.

Key payers covered in this overview include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will gain a concise description of what the code covers, the typical settings where the procedure is performed, and common billing modifiers associated with procedural variability. The publication outlines clinical context for when an anorectal wall biopsy is used, summarizes payer coverage landscape, and highlights operational considerations such as site-of-service determination and claim components (procedure plus pathology). This resource is intended to support coding accuracy, clinical documentation alignment, and administrative clarity for clinicians, coders, and revenue cycle professionals operating at a national level.

Data not available in the input: associated taxonomies, specific ICD-10 diagnoses, related codes, and service-line detail.