Notes: Sumario: Against the background of aging societies and increasing life expectancies, the protection of individuals from outliving their savings has become increasingly relevant. Annuities represent insurance against longevity risk and can prevent old-age poverty. The aim of this article is to present the current state of theoretical, empirical and experimental evidence with regard to annuitization decisions. Toward this end, we conduct a systematic literature review that includes 89 articles. Based on this, we study welfare effects of mandatory annuitization, annuitization rates and the optimal fraction of wealth to be annuitized, as well as determinants of retirees' choice to annuitize and their impact on annuity demand. Finally, we present possible solutions for overcoming the low uptake of annuities based on its causes. One main result is that behavioral biases in annuitization decisions particularly require considerably more theoretical research and empirical evidence, and that theoretical models already appear to well explain empirically observed annuitization rates.