Description: Process risk, estimation error, model uncertainty, trend risk and catastrophe risk are the five main components of longevity risk uncertainty. In the face of this daunting uncertainty, what should the actuarial practitioner do? This session focuses on assessing model uncertainty, process risk and estimation error in mortality modeling. Besides discussing the theory behind methods for performing the assessment, presenters provide attendees with practical examples using R to help them in applying the methodologies and concepts presented.