Immunization with hepatitis B vaccine is often done without prescreening the potential vaccine recipients for evidence of prior hepatitis B virus infection. Prior infection by hepatitis B virus is not a contradiction to the use of hepatitis B vaccine. The prevalence of hepatitis B infection, and the cost of the vaccine combine to render the strategy of immunization without prescreening less expensive than prescreening and then immunization only those without evidence of prior hepatitis B virus infection. Prescreening will diagnose chronic hepatitis B infection, for which effective therapy exists. The likelihood that prescreening will be the less expensive strategy and that prescreening will diagnose chronic hepatitis B infection is directly related to the population prevalence of prior hepatitis B virus infection. The Nova Southeastern University College of Osteopathic Medicine immunizes all incoming medical students with hepatitis B vaccine without prescreening. These medical students are a population more diverse that of the United States as a whole and in which the estimate of a prevalence of prior hepatitis B infection of 5 % is likely to be an underestimate. This study is a serologic screening of the incoming medical students for markers of prior hepatitis B infection. This will generate an estimate of the prevalence of chronic hepatitis B infection. Additionally, it will allow the generation of an equation (Equation 1), relating the cost benefit of surveying for markers of prior hepatitis B vaccine to demographic characteristics of the population to be surveyed. This equation will then be utilized to select the optimal economic strategy for hepatitis B immunization in a population of any degree of diversity.