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CPT 43631: Partial Gastrectomy with Gastroduodenostomy

CPT code 43631 represents a partial gastrectomy with gastroduodenostomy—excision of diseased stomach tissue and reconnection of the stomach remnant to the duodenum to preserve continuity of the digestive tract. This operation is principally used in the surgical management of gastric cancer and other indications requiring removal of part of the stomach. Nationally, the code is relevant to hospital-based surgical services, resource utilization for major abdominal surgery, and postoperative care pathways.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical context for the procedure, typical sites of service, and payer coverage landscape. The publication also provides benchmarks commonly used in surgical billing reviews, coding guidance considerations, and policy updates that affect coverage and documentation standards. Clinicians and billing professionals will gain insight into appropriate use cases for the code, expected resource intensity, and factors that influence payer adjudication of inpatient surgical claims.

Data not available in the input for specific modifiers, associated taxonomies, ICD-10 diagnoses, and related codes is noted where applicable elsewhere in the publication.

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Billing Code Overview

CPT code 43631 describes a surgical procedure in which the provider excises the diseased portion of the stomach and reconnects the remnant of the stomach to the duodenum to maintain an uninterrupted digestive tract. This procedure is typically performed for patients with gastric cancer or other conditions requiring partial gastrectomy with primary reconstruction.

Service type: Major open or minimally invasive abdominal surgery for resection of gastric tissue and reconstruction (partial gastrectomy with gastroduodenostomy).
Typical site of service: Inpatient hospital operating room, frequently requiring postoperative inpatient care.

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CPT 43631: Partial Gastrectomy with Gastroduodenostomy

Data not available in the input for specific modifiers, associated taxonomies, ICD-10 diagnoses, and related codes is noted where applicable elsewhere in the publication.

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Billing Code Overview

Service type: Major open or minimally invasive abdominal surgery for resection of gastric tissue and reconstruction (partial gastrectomy with gastroduodenostomy).
Typical site of service: Inpatient hospital operating room, frequently requiring postoperative inpatient care.

Clinical & Coding Specifications

Clinical Context

A 64-year-old male presents with progressive epigastric pain, early satiety, unintentional weight loss, and an upper endoscopy showing an ulcerated mass in the distal stomach. Biopsy confirms adenocarcinoma of the gastric antrum. Preoperative staging with CT chest/abdomen/pelvis shows a localized tumor without distant metastasis. The surgical oncology team schedules an elective distal gastrectomy with primary reconstruction via gastroduodenostomy (Billroth I) to remove the diseased portion of the stomach and restore continuity of the gastrointestinal tract. The patient is admitted to an acute care hospital for preoperative evaluation, general anesthesia is provided by an anesthesiologist, and the procedure is performed in the operating room by a surgical oncologist or general surgeon. Postoperative care includes inpatient monitoring for hemodynamic stability, pain control, early ambulation, bowel function assessment, and discharge planning with outpatient oncology follow-up for adjuvant therapy decisions.

Coding Specifications

Modifier	Description	When to Use
`00`	No modifier on file / default	Rarely reported; some payors use as a system placeholder.
`11`	Active/regular physician	When reporting the surgeon as the primary performing physician (often default).
`22`	Increased procedural services	When intraoperative complexity significantly increases work (extensive adhesiolysis, unexpected findings).
`52`	Reduced services	When a planned gastrectomy is partially performed or aborted with reduced work.
`53`	Discontinued procedure	If the operation is started but terminated for patient safety before completion.
`62`	Two surgeons	When two qualified surgeons perform distinct portions of the gastrectomy due to complexity.
`63`	Procedure performed on infants (<4kg)	Rarely applicable; only used if patient size/age criteria met.
`78`	Unplanned return to operating room within global period	For a return to OR related to the initial gastrectomy during the global period.
`80`	Assistant surgeon	When a qualified assistant provides surgical assistance.
`81`	Minimum assistant surgeon	When a trainee or assistant provides minimal assistance as defined by payor rules.
`82`	Assistant surgeon (unusual circumstance)	When qualified assistant is not available and an assistant is necessary under unusual circumstances.
`58`	Staged or related procedure or procedure during postoperative period	When the gastrectomy is planned as part of a staged treatment.
`26`	Professional component	If reporting only the physician’s professional component for a service with a technical component (rare for operative codes).

Taxonomy Code	Specialty	Notes
`207P00000X`	General Surgery	Most common specialty performing gastrectomy for malignancy.
`2080P0007X`	Surgical Oncology	Surgeons with focus on oncologic resections often perform this procedure.
`207L00000X`	Thoracic Surgery	May be involved if combined esophagogastric resections are required.
`2086S0127X`	Transplant Surgery	Occasionally involved in complex upper abdominal resections and reconstructions.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C16.2`	Malignant neoplasm of body of stomach	Common location for distal gastrectomy when tumor involves gastric body.
`C16.1`	Malignant neoplasm of fundus of stomach	Tumors in proximal stomach may alter extent of resection; relevant for surgical planning.
`C16.4`	Malignant neoplasm of distal (antrum) of stomach	Typical indication for distal/subtotal gastrectomy with gastroduodenostomy.
`C16.0`	Malignant neoplasm of cardia	May require extended resection; influences reconstruction choice.
`D37.4`	Neoplasm of uncertain behavior of stomach	Sometimes prompts surgical excision when malignancy cannot be excluded.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`43842`	Partial gastrectomy, distal subtotal (e.g., Billroth I or II) with gastrojejunostomy	Alternative reconstruction option (Billroth II) when gastroduodenostomy is not feasible during distal gastric resections.
`43632`	Gastric resection with reconstruction, other techniques (e.g., gastrojejunostomy)	Related procedure code for subtotal gastrectomy with different reconstructive approach.
`99223`	Initial hospital care, high severity	Typical inpatient evaluation and management on the day of surgery for complex surgical patients.
`99100`	Anesthesia for procedures on the abdominal region (example)	Represents the anesthesia services typically reported by anesthesiology for a major abdominal operation.
`43845`	Revision of gastroenterostomy	May be used if postoperative complication requires revision of the reconstructive anastomosis.

CPT 43605: Open Biopsy and Excision of Gastric Lesion

CPT-43610-GASTRIC-EXPLORATION-LESION-EXCISION

CPT 43610: Surgical Exploration of Stomach with Lesion Excision

CPT-43611-GASTRIC-TUMOR-EXCISION-SURGICAL-ONCOLOGY

CPT 43611: Excision of Cancerous Stomach Tumor

CPT-43620-ESOPHAGOENTEROSTOMY-AFTER-GASTRECTOMY

CPT 43620: Esophagoenterostomy After Gastrectomy

CPT-43621-TOTAL-GASTRECTOMY-SMALL-BOWEL-ANASTOMOSIS

CPT 43621: Total Gastrectomy with Small-Bowel Anastomosis

CPT-43622-TOTAL-GASTRECTOMY-ESOPHAGODUODENAL-POUCH-RECONSTRUCTION

CPT 43622: Total Gastrectomy with Esophagoduodenal Pouch Reconstruction

CPT-43632-PARTIAL-GASTRECTOMY-WITH-GASTROJEJUNOSTOMY

CPT 43632: Partial Gastrectomy with Gastrojejunostomy Reconstruction

CPT-43633-PARTIAL-GASTRECTOMY-STOMACH-RESECTION-RECONSTRUCTION

CPT 43633: Partial Gastrectomy with Small Bowel Anastomosis

CPT-43634-PARTIAL-GASTRECTOMY-WITH-INTESTINAL-POUCH-RECONSTRUCTION

CPT 43634: Partial Gastrectomy With Intestinal Pouch Reconstruction

CPT-43635-GASTRIC-RESECTION-WITH-VAGOTOMY

CPT 43635: Gastric Resection with Vagotomy

Showing 1–10 of 12

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Jul 29, 2026.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Jul 29, 2026.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Jul 29, 2026.

Published by

Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.

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.

Clinical & Coding Specifications

Clinical Context

Coding Specifications

Modifier	Description	When to Use
`00`	No modifier on file / default	Rarely reported; some payors use as a system placeholder.
`11`	Active/regular physician	When reporting the surgeon as the primary performing physician (often default).
`22`	Increased procedural services	When intraoperative complexity significantly increases work (extensive adhesiolysis, unexpected findings).
`52`	Reduced services	When a planned gastrectomy is partially performed or aborted with reduced work.
`53`	Discontinued procedure	If the operation is started but terminated for patient safety before completion.
`62`	Two surgeons	When two qualified surgeons perform distinct portions of the gastrectomy due to complexity.
`63`	Procedure performed on infants (<4kg)	Rarely applicable; only used if patient size/age criteria met.
`78`	Unplanned return to operating room within global period	For a return to OR related to the initial gastrectomy during the global period.
`80`	Assistant surgeon	When a qualified assistant provides surgical assistance.
`81`	Minimum assistant surgeon	When a trainee or assistant provides minimal assistance as defined by payor rules.
`82`	Assistant surgeon (unusual circumstance)	When qualified assistant is not available and an assistant is necessary under unusual circumstances.
`58`	Staged or related procedure or procedure during postoperative period	When the gastrectomy is planned as part of a staged treatment.
`26`	Professional component	If reporting only the physician’s professional component for a service with a technical component (rare for operative codes).

Taxonomy Code	Specialty	Notes
`207P00000X`	General Surgery	Most common specialty performing gastrectomy for malignancy.
`2080P0007X`	Surgical Oncology	Surgeons with focus on oncologic resections often perform this procedure.
`207L00000X`	Thoracic Surgery	May be involved if combined esophagogastric resections are required.
`2086S0127X`	Transplant Surgery	Occasionally involved in complex upper abdominal resections and reconstructions.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C16.2`	Malignant neoplasm of body of stomach	Common location for distal gastrectomy when tumor involves gastric body.
`C16.1`	Malignant neoplasm of fundus of stomach	Tumors in proximal stomach may alter extent of resection; relevant for surgical planning.
`C16.4`	Malignant neoplasm of distal (antrum) of stomach	Typical indication for distal/subtotal gastrectomy with gastroduodenostomy.
`C16.0`	Malignant neoplasm of cardia	May require extended resection; influences reconstruction choice.
`D37.4`	Neoplasm of uncertain behavior of stomach	Sometimes prompts surgical excision when malignancy cannot be excluded.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`43842`	Partial gastrectomy, distal subtotal (e.g., Billroth I or II) with gastrojejunostomy	Alternative reconstruction option (Billroth II) when gastroduodenostomy is not feasible during distal gastric resections.
`43632`	Gastric resection with reconstruction, other techniques (e.g., gastrojejunostomy)	Related procedure code for subtotal gastrectomy with different reconstructive approach.
`99223`	Initial hospital care, high severity	Typical inpatient evaluation and management on the day of surgery for complex surgical patients.
`99100`	Anesthesia for procedures on the abdominal region (example)	Represents the anesthesia services typically reported by anesthesiology for a major abdominal operation.
`43845`	Revision of gastroenterostomy	May be used if postoperative complication requires revision of the reconstructive anastomosis.

CPT 43605: Open Biopsy and Excision of Gastric Lesion

CPT-43610-GASTRIC-EXPLORATION-LESION-EXCISION

CPT 43610: Surgical Exploration of Stomach with Lesion Excision

CPT-43611-GASTRIC-TUMOR-EXCISION-SURGICAL-ONCOLOGY

CPT 43611: Excision of Cancerous Stomach Tumor

CPT-43620-ESOPHAGOENTEROSTOMY-AFTER-GASTRECTOMY

CPT 43620: Esophagoenterostomy After Gastrectomy

CPT-43621-TOTAL-GASTRECTOMY-SMALL-BOWEL-ANASTOMOSIS

CPT 43621: Total Gastrectomy with Small-Bowel Anastomosis

CPT-43622-TOTAL-GASTRECTOMY-ESOPHAGODUODENAL-POUCH-RECONSTRUCTION

CPT 43622: Total Gastrectomy with Esophagoduodenal Pouch Reconstruction

CPT-43632-PARTIAL-GASTRECTOMY-WITH-GASTROJEJUNOSTOMY

CPT 43632: Partial Gastrectomy with Gastrojejunostomy Reconstruction

CPT-43633-PARTIAL-GASTRECTOMY-STOMACH-RESECTION-RECONSTRUCTION

CPT 43633: Partial Gastrectomy with Small Bowel Anastomosis

CPT-43634-PARTIAL-GASTRECTOMY-WITH-INTESTINAL-POUCH-RECONSTRUCTION

CPT 43634: Partial Gastrectomy With Intestinal Pouch Reconstruction

CPT-43635-GASTRIC-RESECTION-WITH-VAGOTOMY

CPT 43635: Gastric Resection with Vagotomy

Showing 1–10 of 12

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Jul 29, 2026.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Jul 29, 2026.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Jul 29, 2026.

Published by

Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.

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CPT 43631: Partial Gastrectomy with Gastroduodenostomy

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Billing Code Overview

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CPT 43631: Partial Gastrectomy with Gastroduodenostomy

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Billing Code Overview

Clinical & Coding Specifications

Clinical Context

Coding Specifications

Related Diagnoses

Related CPT Codes

Related Codes

References

Clinical & Coding Specifications

Clinical Context

Coding Specifications

Related Diagnoses

Related CPT Codes

Related Codes

References