Microsimulation models are characterized by simulation of individual event histories for an idealized population or cohort of interest. This workshop will present current uses of microsimulation models, including estimation of cost effectiveness and population-effects of cancer screening intervention, though the focus will be on population-based microsimulation of cancer incidence and mortality. We will briefly review the key aspects of microsimulation modeling: 1) model building; 2) parameter calibration; 3) model validation; and 4) model application and interpretation.