CPT 43645 Reimbursement Benchmarks & Policy | OpenPayer

Summary & Overview

CPT 43645: Laparoscopic Gastric Bypass with Small Intestine Reconstruction

CPT code 43645 is a critical billing code for laparoscopic gastric bypass surgery with small intestine reconstruction, a procedure widely used in the treatment of severe obesity. This code is central to bariatric surgery programs across the United States, reflecting the growing demand for surgical interventions that address obesity and its related health risks. The procedure is typically performed in an inpatient hospital setting and is recognized by major national payers, including Aetna, Blue Cross Blue Shield, Cigna Health, Medicare, and UnitedHealthcare.

This publication provides a comprehensive overview of CPT code 43645, including payer coverage, clinical context, and policy updates relevant to bariatric surgery. Readers will gain insight into the procedure's role in obesity management, the typical patient population, and the importance of accurate coding for reimbursement and compliance. The analysis also highlights benchmarks and trends in payer policies, offering a clear understanding of how this code is utilized in clinical practice and its impact on healthcare delivery. Key modifiers and associated taxonomies are discussed to ensure clarity in billing and documentation. This resource is designed for healthcare professionals, administrators, and policy analysts seeking up-to-date information on bariatric surgery coding and coverage.

AetnaBlue Cross Blue ShieldCigna HealthMedicareUnitedHealthcareCPT 43645bariatric surgerygastric bypasslaparoscopyinpatient hospitalmedical billingobesity treatmentclinical codingpolicy updateprocedure overview

CPT Code Overview

CPT code 43645 describes a laparoscopic surgical gastric restrictive procedure that includes gastric bypass and small intestine reconstruction to limit absorption. This procedure is a form of bariatric surgery designed to help patients with severe obesity achieve significant weight loss by reducing the size of the stomach and rerouting the small intestine. The typical site of service for this procedure is an inpatient hospital setting, specifically at Place of Service 21.

Clinical & Coding Specifications

Clinical Context

A typical patient scenario involves an adult with morbid obesity, often defined by a body mass index (BMI) of 40 or greater, or a BMI of 35 or greater with associated comorbidities. The patient has failed to achieve significant weight loss through conservative measures such as diet, exercise, and medical management. After multidisciplinary evaluation, the patient is scheduled for a laparoscopic gastric bypass procedure with small intestine reconstruction to limit absorption. The procedure is performed in an inpatient hospital setting, with preoperative assessment, surgical intervention, and postoperative monitoring for complications and nutritional status.

Coding Specifications

Modifier 22: Increased Procedural Services. Used when the procedure requires substantially greater effort due to factors such as patient complexity or intraoperative findings.
Modifier 51: Multiple Procedures. Used when more than one surgical procedure is performed during the same operative session.

Modifier Code	Description
`22`	Increased Procedural Services

National Reimbursement Benchmarks

Nationally, the mean rate for CPT code 43645 under Medicare is $1,727.06, while the average commercial benchmark (BUCA) is $2,530.47. This represents a difference of $803.41, with commercial rates significantly higher than Medicare. UnitedHealth Group has the highest mean rate at $3,305.15, and Cigna also stands out with a mean rate of $2,997.50.

Rate dispersion, measured by the difference between the 75th and 25th percentiles, varies across payers. Medicare shows the tightest range at $132.00, indicating relatively consistent rates. In contrast, UnitedHealth Group exhibits the widest dispersion at $1,957.00, reflecting substantial variability in contracted rates. Cigna and BUCA also display broad ranges, while Aetna and Blue Cross Blue Shield are more moderate.

The table and chart below present a detailed breakdown of national mean rates and percentile benchmarks for each payer.

State Benchmarks

State: Alaska1 / 50

Alaska Benchmarks

Alaska exhibits a wide range in reimbursement rates for CPT code 43645, with the highest mean rate from Aetna at $8,640.62 and the lowest from Medicare at $1,708.12. The rate spread, calculated as the difference between the 75th and 25th percentiles, is particularly notable for Cigna ($2,413.90) and BUCA ($2,704.59), indicating significant variability in commercial payer rates. In contrast, Aetna's rates are tightly clustered, with all percentiles at $9,751.00, suggesting uniformity in negotiated rates for this payer.

Compared to national averages, Alaska's commercial payers consistently reimburse at much higher levels, with Aetna's mean rate more than four times the national mean and other payers also showing substantial premiums. The table and chart below present the full breakdown of payer-specific rates and percentiles for Alaska, highlighting the state's unique reimbursement landscape for this procedure.

Key Insights for Alaska

Aetna is the highest paying payer in Alaska for CPT 43645, with a mean rate of $8,640.62, while Medicare is the lowest at $1,708.12.
All commercial payers in Alaska reimburse at significantly higher rates than their national averages, with Aetna's mean rate more than four times the national mean.
The rate spread for commercial payers is substantial, with Cigna showing the widest gap between the 25th and 75th percentiles ($2,413.90), indicating notable variability in negotiated rates.

CPT 43653: Gastric Tube Placement for Enteral Access

43644-LAPAROSCOPY-SURGICAL-GASTRIC-RESTRICTIVE-PROCEDURE-WITH

CPT 43644: Laparoscopic Gastric Bypass with Roux-en-Y Gastroenterostomy

CPT-43651-LAPAROSCOPIC-TRUNCAL-VAGOTOMY-FOR-DUODENAL-ULCER

CPT 43651: Laparoscopic Truncal Vagotomy for Duodenal Ulcer

CPT-43648-LAPAROSCOPIC-GASTRIC-NEUROSTIMULATOR-ELECTRODE-MANAGEMENT

CPT 43648: Laparoscopic Management of Gastric Neurostimulator Electrodes

CPT-43647-LAPAROSCOPIC-GASTRIC-STIMULATION-ELECTRODE-PLACEMENT

CPT 43647: Laparoscopic Gastric Stimulation Electrode Placement

CPT-43652-LAPAROSCOPIC-SELECTIVE-HIGHLY-SELECTIVE-VAGOTOMY

CPT 43652: Laparoscopic Selective or Highly Selective Vagotomy

CPT-43659-UNLISTED-LAPAROSCOPIC-STOMACH-PROCEDURE

CPT 43659: Unlisted Laparoscopic Procedure on the Stomach

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.

Taxonomy Code	Specialty Name
`208600000X`	Surgery Physician
`208D00000X`	General Practice Physician
`208B00000X`	Obesity Medicine Physician