In gastroesophageal reflux disease (GERD), stomach contents flow up and into the esophagus, which causes heartburn. Medicines called proton-pump inhibitors (PPIs) decrease the amount of acid the stomach makes. If heartburn resolves with PPIs, GERD is the likely diagnosis. Another test for GERD is to examine the esophagus with an instrument passed through the mouth (upper endoscopy). Narrowing of the esophagus (strictures) and esophageal cancer are long-term complications of GERD. Approximately 10% of people with long-term heartburn develop an abnormal lining to the esophagus (called Barrett esophagus) and a higher risk for esophageal cancer. Before cancer develops, the cells lining the esophagus may show dysplasia (precancerous changes). Barrett or dysplasia can be diagnosed with endoscopy and biopsies. The benefits of using endoscopy to routinely screen people with GERD for Barrett and cancer are uncertain. Many people have GERD, but few develop cancer. The ACP developed these recommendations to help doctors make good decisions about when to refer patients with GERD for endoscopy.