Why has old-age security become less solidaristic and increasingly tied to risky capitalist markets? Drawing on rich archival data that covers more than fifty years of American history, this book argues that the critical driver was policymakers' reactions to capitalist crises and their political imperative to promote capitalist growth. Pension development has followed three paths of marketization in America since the New Deal, each distinct but converging: occupational pension plans were adopted as an alternative to real increases in Social Security benefits after World War II; private pension assets were then financialized and invested into the stock market; and, since the 1970s, traditional pension plans have come to be replaced with riskier retirement plans. Comparing each episode of change, the book mounts a forceful challenge to common understandings of America's private pension system and offers an alternative political economy of the welfare state. The book weaves together a theoretical framework that helps to explain pension marketization with structural mechanisms that push policymakers to intervene to promote capitalist growth and avoid capitalist crises and contingent historical factors that both drive them to intervene in the particular ways they do and shape how their interventions bear on welfare change. By emphasizing the capitalist context in which policymaking occurs, the book turns our attention to the structural factors that drive policy change. The book urges the reader to reconsider how capitalism itself constrains policymaking.