This paper presents a preliminary econometric analysis on how different alternative plans affect the utilization of health care services in Switzerland. The data come from the 1992-1993 Swiss Health Survey (SHS). We briefly describe some institutional aspects of the Swiss health system which prevailed at the time of the SHS, with particular emphasis on health insurance plans and payment system of providers. We estimate a simultaneous two equation model containing latent variables in order to compare the probability of having at least one inpatient stay given that the insured has used some medical treatment for those who have purchased only a 'basic insurance' plan and those who have purchased a supplemental insurance. [Authors]