The Puerto Rico Committee of Experts and Advisors on Climate Change (CEACC), attached to the Department of Natural and Environmental Resources (DRNA), recruited the firms Technical Studies, Inc. and Tetra Tech to carry out a study on the cost of climate inaction for Puerto Rico. The main objective of the study is to calculate the monetary costs that would result if adaptation measures are not currently managed and implemented in the face of the expected effects of climate change. Most of the studies reviewed analyze the cost of inaction from the perspective of reducing greenhouse gases (Bueno, 2008; Nordhaus, 2017; Deloitte, 2022; Ackerman & Stanton, 2008; Bosello & Parrado, 2014). The action in this conceptual framework is the implementation of a greenhouse gas policy in order to achieve a goal of stopping the rise in global temperature. Although this component is necessary, it is most likely insufficient to analyze the cost of inaction in Puerto Rico given the large number of impacts that the archipelago will receive from climate change. Puerto Rico, like other small and island developing states (SIDS), will experience the impacts of climate change disproportionately to its carbon footprint, since it has no decisive impact on the increase in temperature and will suffer greater damage from rising sea levels, erosion and other climatic factors. For this reason, the analysis must take into account the costs of adaptation policies to mitigate the effects of climate change in Puerto Rico. The CEACC specifically requested that damage associated with several parameters of climate change be evaluated, such as rising sea levels and catastrophic hurricanes. This executive summary includes information on the methods used in the development of the exercise, as well as the findings (estimated costs and impacts), important aspects that should be known about the study (such as clarifications on the data and assumptions used), a brief summary of the expected climate scenario for Puerto Rico and a summary of the conclusions of the study.