What determines the maturity structure of debt? In this article, I develop a simple model to explore how the optimal maturity of debt issued by a firm (or a country) depends both on the firm’s cyclical state and other features of the economic environment in which it operates. I find that firms with better current earnings and better growth prospects issue debt with longer maturity, while firms operating in more-volatile environments issue debt with shorter maturity. Yield to maturity is a poor indicator of the risk of debt issued by a firm. The reason is simple: Yield to maturity captures both default risk and a component that is a pseudo term premium. In the model, the market does require a term premium and one appears only because of the risk of default. It is not possible to separate the impact of maturity and risk.