Disasters can come suddenly, against our will. Therefore, humans must be aware of the losses caused by these disasters. One solution to minimize the risk of loss is to transfer the risk to an insurance company. As a result of these circumstances, insurance companies have the possibility or opportunity to pay claims suddenly. Thus, companies must always have funds to meet their obligations, so there is a need for premium reserves. This paper will discuss the analysis of determining the amount of premium reserves adjusted for last survivor endowment life insurance, with a retrospective principle. Previously, the probability of death was determined using the Gompertz Assumption, whose parameters refer to the 2011 Indonesian Mortality Table (TMI). From the results of this analysis, the expected premium price is based on the Gompertz Assumption Mortality Table. The results are also compared to the price of the premium using the 2011 Mortality Table (TMI) in which, after getting the price of the premium, the next step is to determine the amount of reserves. Reserves obtained will be analyzed, whether accurate or not. The calculation results show that the adjusted premium reserve value is greater when calculated using the 2011 Indonesian Mortality Table (TMI). Therefore, using this Gompertz assumption will reduce the amount of reserves, when compared to using the 2011 Indonesian Mortality Table (TMI).