A practical guide to managing fiscal risk in privately financed infrastructure projects. This resource helps governments make informed decisions about offering guarantees, which can be essential for attracting private investment but pose significant fiscal risks. Drawing on finance, history, economics, and psychology, it reviews the history of government guarantees and identifies cognitive and political obstacles to good decisions. It develops a framework for judging when governments should bear risk, explains how to value guarantees, and discusses public-sector management modifications to improve decision quality. Benefits include: - Improved risk allocation in public-private partnerships - Better management of fiscal risks - Enhanced decision-making regarding guarantees This is for governments, policymakers, infrastructure investors, and public finance professionals seeking to optimize infrastructure financing and manage fiscal exposure.