Introduced during the late 1990's, medical savings accounts (MSAs) increase cost sharing between employers and employees. Despite assurances from proponents claiming cost sharing will stem the tide of rising health care prices and expenditures, skeptics argue that MSA enrollment could reduce utilization of preventative care. This paper estimates preventative care demand models based on data from the National Longitudinal Survey of Youth. These models measure the association between MSA enrollment and the utilization of physicals among adults and doctor visits among children. The models control for endogeneity using a variety of techniques. The results indicate that medical savings account enrollment does not significantly impact the utilization of preventative care.