Projections of disability is an essential tool for insurance companies to set aside reserves for payouts. There are two main ideas behind the models of how this can be done, where one is by using static models and the other is using dynamic models. In this thesis we will set up a dynamic model that is used to predict disability probabilities for different ages. Using Norwegian history of disability, we can form a basis, which further can be used to provide estimates of how disability probabilities will change with the times to come. In addition, we use these results to look at some economic applications that may be of interest to insurance companies. This may be costs associated with portfolios where we look at outcomes for different portfolios.