We used retrospective clinical data from 112 VA hospitals to calibrate a stochastic compartmental simulation model. We modeled a typical VA hospital with 70 beds and its surrounding community with 38,000 enrolled Veterans. The model consisted of 6 patient states—susceptible and colonized individuals who had never been hospitalized, were currently hospitalized, or had a history of hospitalization. Admission, length of stay, inpatient acquisition rates, and mortality rates were calibrated to observed data for MRSA-positive and negative populations. The relative rate of admission of MRSA-positive to negative populations was set to 1.2, based on the relative rate of readmission. Importation among first time admissions was 6.8%; overall it was 10.5%. Readmission rates were calibrated to reflect 15% 30 day readmission[1]. We compared a base-case scenario assuming 5% assumed MRSA prevalence among new Veterans entering the population and a scenario without inpatient transmission. Each scenario was run 200 times.