CPT code 91065 identifies a hydrogen or methane breath test used to diagnose gastrointestinal conditions such as lactose deficiency, fructose intolerance, small intestinal bacterial overgrowth, and to measure oro–cecal transit time. The test is noninvasive, requires fasting (commonly 8–12 hours), and is widely performed in outpatient and ambulatory settings. Nationally, this code matters because breath testing supports targeted clinical management of common digestive complaints and can affect diagnostic pathways and utilization of follow-up procedures.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of clinical indications tied to the code, typical sites of service, and the operational context for use of 91065 in outpatient gastroenterology. The publication summarizes payer coverage considerations, common modifier usage, and how the procedure fits into diagnostic workflows.

The report addresses benchmarks and policy-relevant items such as payer coverage patterns, coding practice implications, and scenarios that commonly prompt testing. It also provides clinical context that clarifies when breath testing is likely to be ordered and what information the test yields for patient management. Data not available in the input are noted where applicable.