The present three studies focused on the development and validation of a multifaceted measure of organizational practices for the aging workforce, the Later Life Workplace Index (LLWI). The first study developed a comprehensive item pool based on expert interview evidence from Germany and the United States. Two further studies among workers across industries in Germany (N = 609, N = 349) provided psychometric evidence. The LLWI comprises nine distinct domains of organizational practices for the aging workforce, namely an age-friendly organizational climate and leadership style, certain work design characteristics, health management, individual development opportunities, knowledge management, the design of the retirement transition, continued employment opportunities, and health and retirement coverage. The final LLWI consists of 80 items in total. In addition, the studies demonstrated that the LLWI measures correlated with older workers’ work outcomes such as stress level, workability, person-organization fit, and post-retirement work intentions in meaningful ways. Applications for the LLWI in research and practice are discussed.