Summary & Overview
CPT 91034: Gastroesophageal Reflux pH Monitoring with Electrode Placement
CPT code 91034 represents placement of a pH electrode for gastroesophageal reflux testing with recording and interpretation of the resulting report. This diagnostic procedure is a key tool in evaluating suspected gastroesophageal reflux disease (GERD) and atypical reflux presentations; its use affects clinical decision-making about medical therapy, surgical referral, and long-term management. Nationally, reimbursement and coverage policies for ambulatory pH monitoring influence access to confirmatory testing and downstream care.
Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the clinical purpose of the code, typical sites of service, and the service type. The publication outlines common billing modifiers and related administrative considerations where available. It also provides benchmarks and payer coverage context where permitted, as well as notes on documentation and interpretation expectations tied to the service.
This summary is oriented to clinicians, billing professionals, and policy analysts seeking a compact reference on CPT code 91034, its clinical role in GER evaluation, and the payer landscape that shapes utilization and access to esophageal pH monitoring nationally.
Billing Code Overview
CPT code 91034 describes a gastroesophageal reflux (GER) test with placement of a pH electrode, in which a sensor that detects acid is placed in the esophagus to measure backflow of stomach acid. The provider records and interprets the pH monitoring report.
Service type: Diagnostic gastroesophageal pH monitoring
Typical site of service: Ambulatory procedure or outpatient gastroenterology setting, such as an endoscopy suite or outpatient clinic where pH probe placement and monitoring are performed.
Clinical & Coding Specifications
Clinical Context
A 45-year-old patient presents to a gastroenterology clinic with a 6-month history of heartburn, regurgitation, and intermittent throat clearing despite a trial of proton pump inhibitor therapy. The gastroenterologist determines that ambulatory esophageal pH monitoring is indicated to quantify acid exposure and correlate symptoms with reflux events. The procedure involves endoscopic or transnasal placement of a pH electrode (catheter or wireless capsule) in the distal esophagus, monitoring over 24–48 hours, and subsequent retrieval of ambulatory data. The provider downloads, analyzes, interprets the pH tracings, and documents a formal report. Typical workflow steps: patient education and consent, placement of pH sensor (in-office or endoscopy suite), ambulatory monitoring period, data retrieval and analysis, interpretation and report generation, and follow-up visit to discuss results. Typical site of service: outpatient gastroenterology clinic, endoscopy suite, or ambulatory surgical center. Service type: diagnostic gastroesophageal reflux testing with placement of a pH electrode and professional interpretation and recording of the report.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the physician interpretation and report if technical component billed separately. |
59 |