CurrentBlue Cross Blue Shield - Rhode IslandPolicy N/A

Esophageal pH monitoring (catheter-based, wireless, impedance-pH) coverage criteria

Governs medical necessity, coverage stance, and coding for catheter-based, wireless (Bravo-type) and impedance-pH esophageal pH monitoring for diagnosis of gastroesophageal reflux disease (GERD) in adults and pediatric patients; affects providers submitting claims to Blue Cross Blue Shield - Rhode Island.

Policy Summary

PayerBlue Cross Blue Shield - Rhode Island

PolicyEsophageal pH monitoring (catheter-based, wireless, impedance-pH) coverage criteria

Policy CodePolicy N/A

Change TypeNo material changes

Effective DateN/A

Next Review DateN/A

Key ActionSubmit clinical documentation supporting indication for pH monitoring when diagnosis is uncertain after evaluation and endoscopy or when considering surgery; prior authorization is not required.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

24-96hmonitoring duration

91034,91035Covered CPTs

91037,91038Not covered CPTs

Not requiredPrior auth

Adults & childrenAge groups

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.

Coverage Criteria

Medically Necessary Indications

Covered when the following clinical circumstances apply:

Primary indication: Patients (adults, children, adolescents) with an uncertain diagnosis of gastroesophageal reflux disease (GERD) after clinical evaluation and endoscopy, or patients being considered for surgical intervention, where pH monitoring will aid diagnosis or management.

Supported by expert clinical opinion and guidelines; evidence for improved health outcomes is limited.

Device/type selection: Testing may be performed using catheter-based pH monitoring (typically 24-hour), wireless mucosal pH capsule monitoring (records up to 96 hours), or impedance-pH monitoring where detection of nonacid or weakly acidic reflux is clinically relevant.

Catheter-based 24-hour monitoring may be considered medically necessary in infants or children unable to report symptoms. Impedance-pH may increase diagnostic yield but effect on outcomes is uncertain.

The following CPT codes are designated not medically necessary for claims submitted to Blue Cross Blue Shield - Rhode Island: 91037 and 91038.

Systematic review of the available evidence shows diagnostic correlation of catheter-based, wireless, and impedance-pH testing with endoscopically defined GERD and with GERD symptoms, but there are no studies demonstrating that pH monitoring (including wireless and impedance-pH) improves clinical outcomes. The evidence is therefore insufficient to determine that these technologies improve health outcomes, and the clinical utility for many indications remains unproven.

Coding

Covered CPT CodesCPTCovered

91034	Esophagus, gastroesophageal reflux test; with nasal catheter electrode(s) placement; recording, analysis and interpretation pH
91035	Esophagus, gastroesophageal reflux test; with mucosal attached telemetry electrode placement; recording, analysis and interpretation pH

Covered CPT Codes (summary)CPTCovered

No codes listed

Not Medically Necessary CPT CodesCPTNot Covered

91037	Esophageal function test, gastroesophageal reflux test with nasal catheter intraluminal impedance electrode(s) placement; recording, analysis and interpretation
91038	Esophageal function test, gastroesophageal reflux test with nasal catheter intraluminal impedance electrode(s) placement; recording, analysis and interpretation; prolonged (greater than 1 hour; Up to 24 hours)

Covered ICD-10 Diagnosis (as listed)ICD-10

G47.30-647.33
J37.0
J69.0
J45.20-J45.99
K21.0-K21.9
P28.0-P28.9
R00.1
R05
R06.81
R06.1

1–10 of 11

1/2

Provider Actions and Billing Notes

Prior Authorization

Prior Authorization Not Required

Prior authorization review is not required for esophageal pH monitoring studies.

Affected codes: CPT 91037, CPT 91038

Note

Clinical Evaluation and Empiric Management Expected

Providers are expected to follow a standard clinical evaluation and empiric medical management for suspected GERD before proceeding to esophageal pH or impedance-pH testing. Testing is typically reserved for patients who do not respond adequately to medical therapy, have recurrent or chronic symptoms, or when endoscopy is nondiagnostic or discordant with the clinical picture.

Documentation Required

Documentation Requirements to Support Indication for pH Monitoring

Background

Gastroesophageal reflux disease (GERD) is often diagnosed clinically and initially managed empirically; endoscopy is used when symptoms persist or to evaluate for complications such as esophagitis. Esophageal pH monitoring—performed either by transnasal catheter (typically about 24 hours) or by a mucosal-attached wireless capsule (records up to 96 hours)—measures acid exposure and can aid diagnosis when clinical evaluation and endoscopy are inconclusive. Impedance-pH monitoring adds detection of nonacid or weakly acidic reflux events and can increase diagnostic yield, but evidence that this added detection changes patient outcomes is limited.

Definitions

Wireless pH monitoring — Bravo-type capsule definition and monitoring duration

DefinitionEndoscopically or manometrically guided attachment of a mucosal pH capsule (eg, Bravo) that records esophageal pH and transmits data via radiofrequency telemetry to a receiver.

Typical monitoring durationRecords pH levels for up to 96 hours.

Data handlingCapsule transmits data to a receiver worn on the belt; data are uploaded to a computer for analysis.

Catheter-based pH monitoring — transnasal catheter placement and typical duration

DefinitionTransnasal placement of a catheter with a pH electrode positioned approximately 5 cm above the upper margin of the lower esophageal sphincter and connected to a data recorder.

Typical monitoring durationRecording of acid reflux events and their duration over a 24-hour period.

Policy Summary

PayerBlue Cross Blue Shield - Rhode Island

PolicyEsophageal pH monitoring (catheter-based, wireless, impedance-pH) coverage criteria

Policy CodePolicy N/A

Change TypeNo material changes

Effective DateN/A

Next Review DateN/A

SourceLink

On This Page

Documentation supporting the medical necessity of pH monitoring should be included in the medical record. This should describe the clinical evaluation, trials of empiric therapy (including agents, doses, and duration), endoscopic findings if performed, and the specific indication for ambulatory pH or impedance-pH monitoring.

Include prior treatments tried and response (medications, dosages, duration)
Include results of endoscopy or note if endoscopy was nondiagnostic

Denial Risk

Denial Risk for CPT 91037 / 91038

Claims submitted with CPT codes 91037 or 91038 may be denied as not medically necessary based on the payer's coverage position. Carefully verify coding and that documentation demonstrates why testing was required after standard evaluation and empiric treatment.

CPT 91037 — Esophageal function test with intraluminal impedance and pH (recording, analysis, interpretation)
CPT 91038 — Prolonged esophageal function test with intraluminal impedance and pH (up to 24 hours)

Patient useRecorder is worn on a waist belt or shoulder strap during the monitoring period.

Impedance-pH monitoring — combined impedance and pH measurement definition and capabilities

DefinitionCombined measurement of intraluminal impedance and pH along multiple electrodes on an esophageal catheter to detect reflux of liquid or gas regardless of pH.

CapabilitiesIdentifies direction of flow and characterizes the refluxate (liquid vs gas) and can detect weakly acidic or nonacid reflux events that pH alone may miss.

Diagnostic yieldSome studies show higher positive test rates compared to pH alone, but impact on patient outcomes is uncertain.