Summary & Overview
CPT 91133: Transcutaneous Electrogastrography for Gastric Motility Evaluation
CPT code 91133 designates diagnostic transcutaneous electrogastrography, a noninvasive test that records gastric myoelectrical activity at baseline and after drug provocation to evaluate suspected gastric motility disorders. This procedure matters nationally as a specialized diagnostic tool used by gastroenterology and motility centers to clarify causes of chronic nausea, vomiting, and other suspected motility dysfunctions when standard testing is inconclusive.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication provides a concise overview of clinical context, coding specifics, and the payer landscape to inform billing, coverage expectations, and documentation priorities across major national payers.
Readers will learn the clinical purpose of the code, typical sites of service, common modifiers and billing considerations (where provided), and what to expect regarding payer coverage patterns and benchmarks. The summary includes practical policy context and benchmarking insights to aid revenue integrity, clinical documentation, and prior authorization workflows. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 91133 describes a diagnostic transcutaneous electrogastrography procedure to measure the electrical activity of the stomach muscles with and without drug-induced provocation of gastric myoelectrical activity. The provider performs this test to evaluate for possible gastric motility disorders, including assessing baseline and provoked gastric myoelectric function.
Service Type: Diagnostic motility testing
Typical Site of Service: Outpatient diagnostic laboratory or gastrointestinal clinic, where noninvasive gastric electrophysiology testing and drug provocation can be performed.
Clinical & Coding Specifications
Clinical Context
A 42-year-old woman with a 12-month history of postprandial nausea, early satiety, abdominal bloating, and intermittent vomiting is referred to gastroenterology to evaluate suspected gastric motility disorder. Prior evaluations included upper endoscopy without anatomic cause and basic laboratory testing. The gastroenterology clinician orders diagnostic transcutaneous electrogastrography to measure gastric myoelectrical activity at baseline and after pharmacologic provocation to assess for dysrhythmias or delayed gastric myoelectrical response.
The typical workflow: the patient arrives to an outpatient gastroenterology or motility laboratory (ambulatory clinic or hospital outpatient department). Skin electrodes are placed on the abdominal surface over the stomach, and baseline myoelectrical recordings are obtained for the prescribed period. A provocation agent (per protocol, e.g., a prokinetic challenge) may be administered, and additional recordings are taken. The technologist documents procedure times, patient tolerance, and any adverse reactions. The interpreting gastroenterologist reviews the recorded tracings, compares baseline and post‑provocation activity, documents findings and impression, and generates the final report for inclusion in the medical record and billing using 91133 for the combined baseline and drug‑provoked transcutaneous electrogastrography.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 |