CPT 45100 Anal Approach Biopsy Reimbursement | OpenPayer

Summary & Overview

CPT 45100: Anal Approach Biopsy of Anorectal Wall

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.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareCPT 45100anorectal biopsysurgical biopsypathologyprocedure codingambulatory surgeryhospital outpatientclinical documentation

Billing Code Overview

CPT code 45100 describes a procedure in which the provider obtains a biopsy of the anorectal wall using an anal approach and sends the tissue to the laboratory for pathologic examination. The procedure is a surgical diagnostic service intended to obtain tissue for histologic analysis to evaluate anorectal disease.

Service type: Surgical biopsy (anorectal)
Typical site of service: Ambulatory surgical center or hospital outpatient department; may also be performed in an office setting equipped for minor surgical procedures depending on clinical circumstances and facility capabilities.

Clinical & Coding Specifications

Clinical Context

A typical patient is a 52-year-old individual presenting to a colorectal clinic with focal anorectal symptoms such as bleeding, persistent pain, a palpable lesion, or an area of induration noted on digital rectal exam or anoscopy. After history and physical exam, including anoscopy or flexible sigmoidoscopy as indicated, the provider identifies a suspicious mucosal or submucosal lesion of the anal canal or distal rectum. The procedure 45100 (anal approach biopsy of the anorectal wall) is scheduled.

The clinical workflow includes pre-procedure assessment (consent, review of anticoagulation, infection control), local anesthesia or conscious sedation as clinically indicated, direct visualization of the lesion with an anoscope or examination under anesthesia when necessary, tissue sampling via forceps or biopsy instrument through the anal canal, specimen labeling and submission to pathology with appropriate clinical history, and post-procedure instructions for wound care and symptom monitoring. Specimens are processed for histopathology to confirm diagnoses such as benign lesions, dysplasia, or malignancy, guiding further management such as excision, surveillance, or referral for oncologic care.

Coding Specifications

Modifier	Description	When to Use
`11`	Managerial or technical services by the attending physician (default)	Use when the procedure is performed as reported with no unusual circumstances.

Related Codes

CPT-45150-RECTAL-STRICTURE-INCISION

CPT 45150: Incision of Rectal Stricture

CPT-45110-ABDOMINOPERINEAL-RESECTION-WITH-COLOSTOMY

CPT 45110: Abdominoperineal Resection with Colostomy

CPT-45113-PROCTECTOMY-ILEOANAL-ANASTOMOSIS-ILEAL-POUCH

CPT 45113: Partial Proctectomy with Ileoanal Anastomosis and Ileal Pouch

CPT-45123-PERINEAL-RECTAL-RESECTION-WITHOUT-ANASTOMOSIS

CPT 45123: Perineal Resection of Diseased Rectum, No Anastomosis

CPT-45126-PELVIC-EXENTERATION-FOR-ADVANCED-COLORECTAL-GENITOURINARY-CANCER

CPT 45126: Pelvic Exenteration for Advanced Colorectal and Genitourinary Cancer

CPT-45121-PULL-THROUGH-RESECTION-ABDOMINAL-PERINEAL-COLORECTAL-ANASTOMOSIS

CPT 45121: Pull-Through Resection with Colorectal Anastomosis

CPT-45108-ANORECTAL-TUMOR-EXCISION

CPT 45108: Excision of Anorectal Muscle Tumor

CPT-45120-ABDOMINOPERINEAL-RECTAL-RESECTION-COLON-ANASTOMOSIS

CPT 45120: Abdominoperineal Rectal Resection with Colon-Anus Anastomosis

CPT-45119-RESTORATIVE-PROCTOCOLECTOMY-WITH-COLONIC-POUCH

CPT 45119: Restorative Proctocolectomy with Colonic Pouch

CPT-45116-POSTERIOR-APPROACH-RECTAL-RESECTION-ANASTOMOSIS

CPT 45116: Posterior Rectal Resection with Colorectal Anastomosis

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Taxonomy Code	Specialty	Notes
2080P0400X	Colorectal Surgery	Colorectal surgeons commonly perform anorectal biopsies, especially for complex or malignant lesions.
207X00000X	General Surgery	General surgeons perform anorectal procedures including biopsies in surgical or endoscopy settings.
207RC0000X	Gastroenterology	Gastroenterologists perform diagnostic anorectal evaluations and biopsies during endoscopic procedures.
363LF0000X	Family Medicine	Family physicians may perform limited anorectal biopsies in office settings when within scope and skill set.
2086S0110X	Proctology (Surgical Subspecialty)	Providers focused on proctologic disorders perform targeted anorectal biopsies and related care.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`K62.5`	Anal fissure	Localized mucosal disruption may be biopsied if atypical or refractory to therapy.
`K62.9`	Disease of anus and rectum, unspecified	Broad code used when specific anorectal pathology is under evaluation; biopsy helps establish diagnosis.
`C21.0`	Malignant neoplasm of anus, external sphincter	Biopsy is required for histologic confirmation of suspected anal cancer.
`C21.8`	Malignant neoplasm of overlapping sites of anus, anal canal and anorectum	Used when tumor spans multiple anorectal sub-sites; biopsy provides tissue diagnosis.
`K60.3`	External hemorrhoids, thrombosed	When a mass is atypical or suspicious, biopsy may be performed to exclude other pathology.
`K62.1`	Rectal prolapse	Mucosal abnormalities noted with prolapse may be biopsied if suspicious for neoplasia.
`K62.7`	Ulcer of anus and rectum	Chronic ulcers require biopsy to exclude malignancy or specific infections.
`A60.9`	Anogenital herpesviral infection, unspecified	Biopsy is rarely used but may be indicated for atypical lesions or when diagnosis is uncertain.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`45330`	Anoscopy, diagnostic, with or without collection of specimen(s) by brushing or washing (separate procedure)	Often performed immediately before `45100` for visualization and targeted biopsy planning.
`45300`	Proctoscopy or anoscopy; diagnostic, rigid	Performed for direct visualization of anal canal lesions prior to biopsy.
`46900`	Destruction of first-degree hemorrhoid, internal or external, any method (separate procedure)	May be performed in the same anatomic region for symptomatic hemorrhoidal disease in a separate encounter.
`44970`	Incision and drainage of anorectal abscess; simple or complicated (separate procedure)	Performed when infection/abscess is present and drainage is required; biopsy may be deferred or separately coded.
`88305`	Level IV surgical pathology, gross and microscopic examination	Represents the common pathology billing level for tissue obtained via `45100` and submitted to the laboratory.