OBJECTIVES: The objective of this study was to evaluate the differences in reported levels of absenteeism and direct medical costs between employees diagnosed with gastroesophageal reflux disease (GERD) and/or peptic ulcer disease (PUD) and a matched-cohort with neither disease. METHODS: Data were extracted from the MarketScan Research Database, a Health Insurance Portability and Accountability Act compliant database consisting of medical and prescription claims of employees linked to the absenteeism files of their employers. Employees with an ICD-9 code for GERD/PUD, and a matched cohort with neither disease, were identified from January 1, 1997 to December 31, 2000. Demographic, absenteeism, and resource-utilization variables were collected for all eligible subjects. Analysis of variance was used to test the null hypothesis that the four populations have equal means of absenteeism rates. RESULTS: In all, 6205 employees with GERD, 2702 with PUD, 3297 with both GERD and PUD, and 42,902 matched control subjects were identified. There was no significant difference between the GERD and PUD groups in health care costs, except total prescription costs that were higher in the GERD group (p <0.001). Work-absenteeism rates appeared to increase in the expected fashion, with lowest rates in the control group and highest rates in the combined group. The magnitude of this difference was 0.3 sickness-related absence days per individual per year between the groups with and without gastrointestinal disease. For all-cause absences, the difference was higher with 1.5 absence days per year. Projections of this data to an average sized Fortune 500 company of 250,000 employees would translate to total direct costs of $312 million and indirect costs of $4.75 million per year. CONCLUSIONS: Direct medical cost and worker absenteeism, in GERD and PUD employees creates a significant burden on the employee community.