Summary & Overview
CPT 45331: Flexible Sigmoidoscopy with Biopsy
CPT code 45331 is a widely utilized billing code in gastroenterology, representing the flexible sigmoidoscopy procedure with biopsy of single or multiple sites. This diagnostic service is essential for the detection and evaluation of colon abnormalities, such as polyps, neoplasms, and unexplained gastrointestinal symptoms. The procedure is typically performed in outpatient hospital settings and is a cornerstone in colorectal disease management.
Major national payers, including Aetna, Blue Cross Blue Shield, Cigna Health, Medicare, and UnitedHealthcare, provide coverage for this service, reflecting its clinical importance and broad applicability. The publication offers a comprehensive overview of policy updates, reimbursement benchmarks, and clinical context relevant to CPT code 45331. Readers will gain insights into payer coverage, typical clinical indications, and related procedural codes, supporting informed decision-making in medical billing and compliance.
Key topics include the role of flexible sigmoidoscopy with biopsy in gastrointestinal diagnostics, common billing modifiers, associated provider taxonomies, and ICD-10 diagnoses frequently linked to this procedure. The article also highlights related CPT codes for similar endoscopic services, offering a clear framework for understanding procedural distinctions and billing practices. This summary serves as a resource for healthcare professionals, administrators, and policy analysts seeking up-to-date information on the utilization and coverage of CPT code 45331.
CPT Code Overview
CPT code 45331 represents a flexible sigmoidoscopy procedure with biopsy, either single or multiple. This procedure is performed by physicians specializing in gastroenterology and involves the examination of the lower part of the colon using a flexible scope, with tissue samples taken for further analysis. The typical site of service for this procedure is an outpatient hospital setting, designated as Place of Service 22. Flexible sigmoidoscopy with biopsy is a key diagnostic tool for identifying and evaluating various gastrointestinal conditions, including abnormal growths, bleeding, and other colon pathologies.
Clinical & Coding Specifications
Clinical Context
A patient presents to the outpatient hospital setting with symptoms such as rectal bleeding, abnormal stool findings, or a history of colon polyps. The provider, typically a gastroenterologist, family medicine physician, or internal medicine physician, determines that a flexible sigmoidoscopy with biopsy is clinically indicated. During the procedure, the provider uses a flexible sigmoidoscope to examine the lower colon and rectum, and obtains one or more tissue biopsies for histopathological evaluation. The workflow includes pre-procedure assessment, informed consent, the sigmoidoscopy with biopsy, and post-procedure care. The procedure is commonly performed for diagnostic evaluation of suspected polyps, neoplasms, or unexplained gastrointestinal symptoms.
Coding Specifications
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Modifiers:
- Modifier
26: Used when reporting only the professional component (interpretation and report) of the procedure. - Modifier
TC: Used when reporting only the technical component (equipment, supplies, and technical staff) of the procedure. - Modifier
59: Indicates a distinct procedural service, used when multiple procedures are performed that are not normally reported together. - Modifier
51: Used to indicate multiple procedures performed during the same session.
- Modifier
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Provider Taxonomies:
| Taxonomy Code | Specialty Name |
|---|---|
207RG0100X | Gastroenterology Physician |
207Q00000X | Family Medicine Physician |
207R00000X | Internal Medicine Physician |
These taxonomies represent the specialties commonly performing or supervising the procedure.
Related Diagnoses
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K63.5: Polyp of colon- Relevant for patients with suspected or known colon polyps, which are often biopsied during sigmoidoscopy.
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K92.2: Gastrointestinal hemorrhage, unspecified- Used when the patient presents with GI bleeding, prompting investigation and biopsy.
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R19.5: Other fecal abnormalities- Applied when abnormal stool findings necessitate endoscopic evaluation and biopsy.
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D12.3: Benign neoplasm of colon, unspecified- Indicates benign colon neoplasms, which may be identified and biopsied during the procedure.
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K52.9: Noninfective gastroenteritis and colitis, unspecified- Used for patients with unexplained colitis or gastroenteritis, where biopsy may help determine etiology.
Related CPT Codes
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45330: Sigmoidoscopy, flexible; diagnostic- Used for diagnostic sigmoidoscopy without biopsy. Often performed prior to or in place of
45331if no biopsy is needed.
- Used for diagnostic sigmoidoscopy without biopsy. Often performed prior to or in place of
-
45332: Sigmoidoscopy, flexible; with removal of foreign body- Used when a foreign body is identified and removed during sigmoidoscopy. May be performed in conjunction with or instead of
45331depending on findings.
- Used when a foreign body is identified and removed during sigmoidoscopy. May be performed in conjunction with or instead of
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45333: Sigmoidoscopy, flexible; with removal of tumor(s), polyp(s), or other lesion(s) by hot biopsy forceps- Used when a lesion is removed using hot biopsy forceps. May be an alternative or additional procedure to
45331if removal is required.
- Used when a lesion is removed using hot biopsy forceps. May be an alternative or additional procedure to
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45334: Sigmoidoscopy, flexible; with control of bleeding, any method- Used when the procedure includes control of bleeding. Can be performed alongside
45331if bleeding is encountered.
- Used when the procedure includes control of bleeding. Can be performed alongside
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45335: Sigmoidoscopy, flexible; with directed submucosal injection(s), any substance- Used when submucosal injections are performed during sigmoidoscopy. May be used in combination with
45331for therapeutic purposes.
- Used when submucosal injections are performed during sigmoidoscopy. May be used in combination with
These codes are related by procedural similarity and may be used as alternatives or adjuncts depending on clinical findings during sigmoidoscopy.
National Reimbursement Benchmarks
Medicare's national mean rate for CPT code 45331 is $336.96, which is notably higher than the BUCA (average commercial) mean rate of $231.68. Among commercial payers, UnitedHealth Group has the highest mean rate at $343.04, while Aetna is the lowest at $168.99.
Rate dispersion, measured by the difference between the 75th and 25th percentiles, varies significantly across payers. Medicare shows the tightest range at $43.00, indicating relatively consistent rates nationwide. In contrast, UnitedHealth Group exhibits the widest dispersion at $201.50, reflecting substantial variability in contracted rates. Cigna and Blue Cross Blue Shield also display broad ranges, while Aetna and BUCA are more moderate.
The table and chart below present a detailed breakdown of national mean rates and percentile distributions for each payer.
Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.