Knowing about the profile of the Brazilian population covered by private health plans is very important to guide the National Health Agency policies, the health insurance companies` action strategies in many ways and how the many agents involved should stand toward this process. Our purpose is to do this in the light of the work market situation, taking into account his/her self-reported morbidity, controlling for the demographical and social-economical variables. We start by presenting an exploratory study linking health plan owning with these variables. We then make use of logistic regression models, which have been adjusted to explain de self-reported morbidity according to the individual`s position in the job market, controlling for the demographical variables. The same class of model has also been used as a tool to investigate the existence of Information Asymmetry in this type of contract. Our results show that information asymmetry cases are concentrated in some diseases. We could also find some worker groups very likely to being ill from specific diseases in some specific regions of the country.