Summary & Overview

CPT 45346: Flexible Sigmoidoscopy with Lesion Ablation

CPT code 45346 represents a flexible sigmoidoscopy of the sigmoid colon that includes ablation of a polyp, tumor, or other lesion. This combined diagnostic and therapeutic endoscopic procedure is used to both evaluate and treat lesions in the sigmoid colon and can include predilation, postdilation, and passage for a guide wire when required. Nationally, this code is significant because it captures procedures that can prevent progression of neoplastic lesions and reduce the need for more extensive surgery.

Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Coverage policies, prior authorization requirements, and allowed sites of service vary across these payers; understanding payer behavior affects billing, site selection, and clinical workflow for gastroenterology and colorectal surgery practices.

Readers will learn the clinical scope of CPT code 45346, typical settings where the service is delivered, and the implications for billing and payer engagement. The publication provides benchmarks and policy context relevant to reimbursement and utilization, plus a concise clinical description to aid coding accuracy. Data not available in the input are noted where applicable.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare45346CPTflexible-sigmoidoscopyendoscopylesion-ablationgastroenterologycolorectal-proceduresambulatory-surgery

Billing Code Overview

CPT code 45346 describes a diagnostic and therapeutic flexible sigmoidoscopy of the sigmoid colon with ablation of a polyp, tumor, or other lesion. The procedure involves insertion of a flexible sigmoidoscope to visualize the sigmoid colon and includes lesion ablation; it may also include predilation or postdilation and passage for a guide wire when clinically necessary.

Service type: Flexible sigmoidoscopy with lesion ablation (diagnostic and therapeutic endoscopic procedure)
Typical site of service: Ambulatory surgery center or hospital outpatient department; it may also be performed in endoscopy suites within hospital settings.

Clinical & Coding Specifications

Clinical Context

A 58-year-old patient presents to a gastroenterology ambulatory endoscopy suite with intermittent left lower quadrant cramping and new bright red blood per rectum. After evaluation in clinic, a diagnostic flexible sigmoidoscopy is scheduled to evaluate the distal colon. During the procedure the gastroenterologist visualizes a 1.5 cm sessile polyp in the sigmoid colon and performs endoscopic ablation. The encounter includes pre-procedure assessment, conscious sedation administered by anesthesia personnel when applicable, performance of the flexible sigmoidoscopy with lesion ablation, possible predilation or postdilation if a stricture is encountered, passage of a guide wire if required for adjunctive devices, and recovery in the endoscopy recovery area. Typical sites of service are an outpatient hospital endoscopy unit or an ambulatory surgical center. Usual workflow: clinic evaluation and consent → pre-procedure evaluation and sedation planning → procedure (flexible sigmoidoscopy with lesion ablation) → post-procedure monitoring and discharge instructions.

Coding Specifications

Modifier	Description	When to Use
`25`	Data not available in the input.	Data not available in the input.
`26`	Professional component	Use when reporting only the physician professional component of a procedure when applicable (e.g., interpretation separate from technical service).
`52`	Reduced services	Use when the procedure is partially reduced or not completed as planned but was attempted.
`53`	Discontinued procedure	Use when the procedure is started but discontinued due to extenuating circumstances.
`59`	Distinct procedural service	Use to indicate a distinct procedural service separate from other procedures provided on the same date.
`62`	Two surgeons	Use when two surgeons work together as primary surgeons performing distinct operative duties.
`76`	Data not available in the input.	Data not available in the input.
`78`	Return to OR for related procedure during global period	Use when an unplanned return to the operating/procedure room is required for a related procedure.
`79`	Data not available in the input.	Data not available in the input.
`80`	Assistant surgeon	Use when an assistant surgeon is required and documented for the procedure.
`51`	Multiple procedures	Use when multiple procedures are performed in the same session; sequence by highest RVU code and append `51` as appropriate per payer rules.
`53`	Discontinued procedure	Use when the procedure is terminated after initiation due to patient safety or other reasons.
`59`	Distinct procedural service	Use when procedures are separate and not part of the primary service.

Taxonomy Code	Specialty	Notes
207RG0100X	Gastroenterology	Gastroenterologists most commonly perform flexible sigmoidoscopy with lesion ablation.
207RI0200X	Colon and Rectal Surgery	Colorectal surgeons perform similar endoscopic procedures and may manage complex lesions or complications.
207RN0201X	General Surgery	General surgeons with endoscopy training perform sigmoidoscopy and therapeutic lesion management.
372N00000X	Interventional Radiology	Included when guide wire passage and radiologic assistance are required for adjunct procedures.
2084P0800X	Anesthesiology	Anesthesia providers deliver sedation/monitoring services when conscious sedation or anesthesia is used.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`K63.5`	Polyp of colon	Sigmoidoscopy with ablation addresses symptomatic or detected colonic polyps in the sigmoid colon.
`K92.1`	Melena	Used when lower GI bleeding presents; sigmoidoscopy may identify distal sources amenable to ablation.
`K62.5`	Hemorrhage of anus and rectum	Relevant for evaluation of rectal bleeding where distal lesions are suspected.
`K57.30`	Diverticulosis of large intestine without perforation or abscess	Sigmoidoscopy can be used to evaluate distal diverticular disease when indicated.
`C18.7`	Malignant neoplasm of sigmoid colon	Lesion ablation may be part of palliative or local control strategies for distal malignant lesions.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`45346`	Flexible sigmoidoscopy with ablation of tumor(s), polyp(s), or other lesion(s)	Primary procedure: diagnostic/therapeutic evaluation of sigmoid colon with endoscopic ablation.
`45378`	Colonoscopy, flexible; diagnostic, including collection of specimen(s) by brushing or washing, when performed (separate from biopsy)	Performed when full colon evaluation is indicated or if lesion requires full colonoscopy for access.
`45380`	Colonoscopy, flexible; with biopsy, single or multiple	Performed to obtain tissue sampling of suspicious lesions encountered during or instead of ablation.
`45385`	Colonoscopy, flexible; with removal of tumor(s), polyp(s), or other lesion(s) by snare technique	Alternative therapeutic technique for polypectomy if snare removal is chosen rather than ablation.
`45331`	Sigmoidoscopy, rigid; proctosigmoidoscopy limited	May be used in limited anatomic evaluations when flexible sigmoidoscopy is not performed or available.
`00740`	Anesthesia for lower abdominal procedures (if general or regional anesthesia is used)	Billed when anesthesia services beyond monitored anesthesia care or sedation are provided during the procedure.