Since the early 1980s, employment in the United States has undergone significant transformation as the large corporations that once safeguarded employees with stable jobs and rewards for loyalty have replaced these employment relationships with ones based on cost containment and flexibility. One important consequence of these developments is that firms have abdicated their role as a critical risk bearer in society. Although evidence suggests that firms have increasingly shifted market risks onto their workforce, to date, there have been few detailed analyses exploring what factors have driven this phenomenon. This study adds to our understanding of why firms have transferred risk to their employees by examining the decline of a highly institutionalized practice wherein large U.S. firms used to bear retirement risk: the defined benefit (DB) pension plan. Through a detailed analysis, I show that variance in the presence, power, and interests of shareholders and employees at the firm level differentially affect a firm’s willingness to shift the risk of retirement onto its workers. Specifically, I demonstrate empirically that different types of shareholders have differential effects on a firm’s retirement practices, suggesting that the changing equity ownership structure of large U.S. firms has played a key role in how risk is allocated between workers and firms. Declines in employee power have also played a role because firm levels of unionization positively affect rates of DB participation for both unionized and nonunionized workers.