BACKGROUND & AIMS: Efforts to assess and improve the effectiveness of Barretts esophagus (BE) screening and surveillance are ongoing in the United States. Currently, there are limited population-based data in the United States to guide these efforts. METHODS: We performed a retrospective cohort study using data from large commercial and Medicare Advantage health plans in the United States from 2004 - 2019. We identified individuals with BE and analyzed the proportion who developed EAC. EACs were classified as prevalent EAC (diagnosed within 30 days of index endoscopy), post-endoscopy esophageal adenocarcinoma (PEEC, diagnosed 30 - 365 days after index endoscopy), and incident EAC (diagnosed 365 days or more after index endoscopy). Using this cohort, we performed a nested case-control study to identify factors associated with prevalent EAC at BE diagnosis and study healthcare utilization prior to BE diagnosis. RESULTS: We identified 50,817 individuals with incident BE. Of the 366 who developed EAC, 67.2%, 13.7%, and 19.1% were diagnosed with prevalent EAC, PEEC, and incident EAC respectively. Factors positively associated with prevalent EAC versus BE without prevalent EAC included male sex, dysphagia, weight loss, and Charlson-Deyo comorbidity score. In those with prevalent EAC, most patients with dysphagia or weight loss had their symptoms first recorded within three months of EAC diagnosis. Healthcare utilization rates were similar between those with and without prevalent EAC. CONCLUSIONS: Two-thirds of EACs among individuals with BE are diagnosed at the time of BE diagnosis. Additionally, PEEC accounts for 14% of these EACs. These results may guide future research studies that investigate novel BE diagnostic strategies that reduce the morbidity and mortality of EAC.