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CPT 43520: Pyloromyotomy for Hypertrophic Pyloric Stenosis

CPT code 43520 represents a surgical pyloromyotomy used to correct hypertrophic pyloric stenosis, a common cause of projectile vomiting in infants. This operative procedure is clinically significant because it provides definitive relief of gastric outlet obstruction and is a standard treatment in pediatric surgery. Nationally, proper coding for 43520 affects hospital and ambulatory surgery center billing, quality measurement, and pediatric surgical workflow.

Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context for pyloromyotomy, typical sites of service, and the operational implications of billing 43520 across major payers. The publication outlines common benchmarking topics such as utilization patterns, payer coverage considerations, and coding compliance themes. It also summarizes relevant policy updates and payer-level coverage notes where available. Finally, the report provides operational takeaways for coding accuracy, documentation elements tied to the procedure description, and points of attention for claim submissions. Data not available in the input are noted where applicable.

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Billing Code Overview

CPT code 43520 describes a surgical procedure in which the provider incises the hypertrophied pyloric muscle to correct pyloric stenosis, a condition that narrows the gastric outlet and commonly causes projectile vomiting in infants. The procedure relieves obstruction by splitting the overdeveloped pyloric muscle while preserving the mucosa.

Service type: Surgical procedure (pyloromyotomy)
Typical site of service: Operating room or ambulatory surgical center for operative management of infant pyloric stenosis

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CPT 43520: Pyloromyotomy for Hypertrophic Pyloric Stenosis

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Billing Code Overview

Service type: Surgical procedure (pyloromyotomy)
Typical site of service: Operating room or ambulatory surgical center for operative management of infant pyloric stenosis

Clinical & Coding Specifications

Clinical Context

An infant, typically aged 2–8 weeks, presents with projectile, non-bilious vomiting, poor weight gain, and palpable olive-shaped mass in the right upper quadrant. The pediatrician refers the patient to pediatric surgery after ultrasound confirms hypertrophic pyloric stenosis with an elongated, thickened pyloric channel. Preoperative workflow includes surgical consultation, history and physical, correction of dehydration and electrolyte abnormalities (often hypochloremic, hypokalemic metabolic alkalosis) with intravenous fluids, and anesthesia evaluation. The patient is admitted to the pediatric surgical unit or pediatric ambulatory surgery center depending on clinical stability. The operating surgeon performs a pyloromyotomy (43520) under general anesthesia, making a longitudinal incision through the hypertrophied pyloric muscle to relieve gastric outlet obstruction while preserving the mucosa. Postoperative care includes monitoring for vomiting, feeding advancement per institutional protocol, pain control, and discharge once tolerating feeds and stable. Typical sites of service are the inpatient pediatric surgical unit, pediatric ambulatory surgery center, or hospital operating room staffed for pediatric anesthesia.

Coding Specifications

Modifier	Description	When to Use
`00`	Modifier not in standard lists (placeholder)	Use only if a payor-specific system requires an unspecified modifier code `00`.
`11`	Government payor-specific modifier (placeholder)	Rare; use per specific governmental payer guidance when required.
`22`	Increased procedural service	When the pyloromyotomy requires substantially greater work or time than typical, document and append `22`.
`23`	Unusual anesthesia	When the procedure is performed under local or regional anesthesia instead of general and documentation supports unexpected anesthesia circumstances.
`26`	Professional component	When billing separates professional (surgeon) from technical components (facility/equipment) for services related to the procedure.
`50`	Bilateral procedure	Not typically used for `43520` (single anatomic site); include only if a payer perversely requires bilateral reporting for related paired procedures.
`51`	Multiple procedures	When another reportable procedure is performed during the same operative session in addition to `43520`; append `51` per payer rules.
`52`	Reduced services	When the pyloromyotomy is intentionally partially reduced or abbreviated and documentation supports lesser service.
`53`	Discontinued procedure	When the procedure is started but discontinued due to extenuating circumstances; document reason and append `53`.
`62`	Two surgeons	When two surgeons with distinct skills are required and each bills their portion, with documentation supporting separate work.
`63`	Procedure performed on infants less than 4 kg	Used when payer requires identification of neonatal or very low-weight infant status for additional payment or tracking.
`76`	Repeat procedure by same physician (not in list)	Data not available in the input.
`78`	Return to the operating room for a related procedure during the postoperative period	When a reoperation related to the initial pyloromyotomy occurs during the global period.
`80`	Assistant surgeon	When a surgical assistant (physician) provides assistance and billing rules allow an assistant claim.

Taxonomy Code	Specialty	Notes
2080P0208X	Pediatric General Surgery	Pediatric surgeons most commonly perform `43520` with expertise in neonatal/pediatric anesthetic and perioperative care.
207K00000X	General Surgery	General surgeons with pediatric experience may perform pyloromyotomy in some settings.
207L00000X	Pediatric Medicine	Pediatric hospitalists are commonly involved in preoperative stabilization and postoperative medical management but do not bill the surgical procedure.
207H00000X	Anesthesiology	Pediatric anesthesiologists provide age-appropriate anesthesia care for infants undergoing `43520`.
2084P0205X	Neonatal-Perinatal Medicine	Neonatologists participate when the infant requires NICU-level pre- or postoperative care.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`K31.1`	Hypertrophy of pylorus	Primary diagnosis indicating pyloric muscle hypertrophy; direct indication for pyloromyotomy (`43520`).
`P92.5`	Other feeding problems of newborn	May be present due to vomiting and feeding intolerance associated with pyloric stenosis; supports clinical context.
`E87.5`	Hyperkalemia	Electrolyte disturbance that can occur in the perioperative period; relevant for preoperative correction.
`E87.6`	Hypokalemia	Common metabolic derangement in pyloric stenosis due to vomiting; requires correction before surgery.
`E87.1`	Hypo-osmolality and hyponatremia	Possible electrolyte abnormality from vomiting and dehydration; relevant to perioperative management.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`99100`	Anesthesia for procedures on premature infants or full-term infants less than 20 weeks (This code is illustrative — check payer rules)	Used in anesthesia coding for neonatal patients; relevant when billing anesthesia services for infants undergoing `43520`.
`96360`	Intravenous infusion, hydration; initial, up to 1 hour	Perioperative intravenous fluid resuscitation and correction of dehydration prior to surgery; often provided preoperatively.
`36415`	Collection of venous blood by venipuncture	Preoperative laboratory testing (electrolytes) to assess and correct metabolic derangements before `43520`.
`99221`	Initial hospital inpatient care, per day	Inpatient admission evaluation and management for infants requiring stabilization and postoperative inpatient care surrounding pyloromyotomy.
`99432`	Subsequent hospital care per day (example)	Daily postoperative inpatient E/M during global period when additional physician management is required.
`54505`	Excision of lesion of testis or scrotum (example)	Data not available in the input.

CPT 43500: Gastrotomy for Foreign Body Exploration and Removal

CPT-43501-OPEN-GASTRIC-HEMOSTASIS-STOMACH-INCISION-BLEEDING-VESSEL-LIGATION

CPT 43501: Open Gastric Hemostasis, Incision and Vessel Ligation

CPT-43502-ESOPHAGEAL-LACERATION-REPAIR-HEMOSTASIS

CPT 43502: Repair of Lower Esophageal Laceration to Control Bleeding

CPT-43510-ESOPHAGEAL-STENT-PLACEMENT-PALLIATIVE-STRICTURE-RELIEF

CPT 43510: Esophageal Stent Placement for Stricture Palliation

Frequently Asked Questions

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.

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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`	Modifier not in standard lists (placeholder)	Use only if a payor-specific system requires an unspecified modifier code `00`.
`11`	Government payor-specific modifier (placeholder)	Rare; use per specific governmental payer guidance when required.
`22`	Increased procedural service	When the pyloromyotomy requires substantially greater work or time than typical, document and append `22`.
`23`	Unusual anesthesia	When the procedure is performed under local or regional anesthesia instead of general and documentation supports unexpected anesthesia circumstances.
`26`	Professional component	When billing separates professional (surgeon) from technical components (facility/equipment) for services related to the procedure.
`50`	Bilateral procedure	Not typically used for `43520` (single anatomic site); include only if a payer perversely requires bilateral reporting for related paired procedures.
`51`	Multiple procedures	When another reportable procedure is performed during the same operative session in addition to `43520`; append `51` per payer rules.
`52`	Reduced services	When the pyloromyotomy is intentionally partially reduced or abbreviated and documentation supports lesser service.
`53`	Discontinued procedure	When the procedure is started but discontinued due to extenuating circumstances; document reason and append `53`.
`62`	Two surgeons	When two surgeons with distinct skills are required and each bills their portion, with documentation supporting separate work.
`63`	Procedure performed on infants less than 4 kg	Used when payer requires identification of neonatal or very low-weight infant status for additional payment or tracking.
`76`	Repeat procedure by same physician (not in list)	Data not available in the input.
`78`	Return to the operating room for a related procedure during the postoperative period	When a reoperation related to the initial pyloromyotomy occurs during the global period.
`80`	Assistant surgeon	When a surgical assistant (physician) provides assistance and billing rules allow an assistant claim.

Taxonomy Code	Specialty	Notes
2080P0208X	Pediatric General Surgery	Pediatric surgeons most commonly perform `43520` with expertise in neonatal/pediatric anesthetic and perioperative care.
207K00000X	General Surgery	General surgeons with pediatric experience may perform pyloromyotomy in some settings.
207L00000X	Pediatric Medicine	Pediatric hospitalists are commonly involved in preoperative stabilization and postoperative medical management but do not bill the surgical procedure.
207H00000X	Anesthesiology	Pediatric anesthesiologists provide age-appropriate anesthesia care for infants undergoing `43520`.
2084P0205X	Neonatal-Perinatal Medicine	Neonatologists participate when the infant requires NICU-level pre- or postoperative care.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`K31.1`	Hypertrophy of pylorus	Primary diagnosis indicating pyloric muscle hypertrophy; direct indication for pyloromyotomy (`43520`).
`P92.5`	Other feeding problems of newborn	May be present due to vomiting and feeding intolerance associated with pyloric stenosis; supports clinical context.
`E87.5`	Hyperkalemia	Electrolyte disturbance that can occur in the perioperative period; relevant for preoperative correction.
`E87.6`	Hypokalemia	Common metabolic derangement in pyloric stenosis due to vomiting; requires correction before surgery.
`E87.1`	Hypo-osmolality and hyponatremia	Possible electrolyte abnormality from vomiting and dehydration; relevant to perioperative management.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`99100`	Anesthesia for procedures on premature infants or full-term infants less than 20 weeks (This code is illustrative — check payer rules)	Used in anesthesia coding for neonatal patients; relevant when billing anesthesia services for infants undergoing `43520`.
`96360`	Intravenous infusion, hydration; initial, up to 1 hour	Perioperative intravenous fluid resuscitation and correction of dehydration prior to surgery; often provided preoperatively.
`36415`	Collection of venous blood by venipuncture	Preoperative laboratory testing (electrolytes) to assess and correct metabolic derangements before `43520`.
`99221`	Initial hospital inpatient care, per day	Inpatient admission evaluation and management for infants requiring stabilization and postoperative inpatient care surrounding pyloromyotomy.
`99432`	Subsequent hospital care per day (example)	Daily postoperative inpatient E/M during global period when additional physician management is required.
`54505`	Excision of lesion of testis or scrotum (example)	Data not available in the input.

CPT 43500: Gastrotomy for Foreign Body Exploration and Removal

CPT-43501-OPEN-GASTRIC-HEMOSTASIS-STOMACH-INCISION-BLEEDING-VESSEL-LIGATION

CPT 43501: Open Gastric Hemostasis, Incision and Vessel Ligation

CPT-43502-ESOPHAGEAL-LACERATION-REPAIR-HEMOSTASIS

CPT 43502: Repair of Lower Esophageal Laceration to Control Bleeding

CPT-43510-ESOPHAGEAL-STENT-PLACEMENT-PALLIATIVE-STRICTURE-RELIEF

CPT 43510: Esophageal Stent Placement for Stricture Palliation

Frequently Asked Questions

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 43520: Pyloromyotomy for Hypertrophic Pyloric Stenosis

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Billing Code Overview

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CPT 43520: Pyloromyotomy for Hypertrophic Pyloric Stenosis

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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

CPT 43520: Pyloromyotomy for Hypertrophic Pyloric Stenosis

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Billing Code Overview

CPT 43520: Pyloromyotomy for Hypertrophic Pyloric Stenosis

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Billing Code Overview

Clinical & Coding Specifications

Clinical Context

Coding Specifications

Related Diagnoses

Related CPT Codes

Related Codes

What does CPT 43520 describe and where is it typically performed?

What preoperative clinical workup and stabilization are described before pyloromyotomy?

Which modifiers are commonly noted for 43520 and when might they be used?

What related CPT codes are commonly billed in the perioperative period for pyloromyotomy?

Which diagnosis codes and payers are referenced as relevant to claims for CPT 43520?

References

Clinical & Coding Specifications

Clinical Context

Coding Specifications

Related Diagnoses

Related CPT Codes

Related Codes

What does CPT 43520 describe and where is it typically performed?

What preoperative clinical workup and stabilization are described before pyloromyotomy?

Which modifiers are commonly noted for 43520 and when might they be used?

What related CPT codes are commonly billed in the perioperative period for pyloromyotomy?

Which diagnosis codes and payers are referenced as relevant to claims for CPT 43520?

References