Research on measures for organizational practices targeted toward older employees has grown during the past decade. However, existing measures tend to capture the construct with unidimensional scales, use single-item operationalizations, or focus on specific domains. Thus, the Later Life Workplace Index (LLWI) was developed to serve as a multidimensional framework for measuring organizational practices for the aging workforce. The LLWI covers 9 domains, namely organizational climate, leadership, work design, health management, individual development, knowledge management, transition to retirement, continued employment after retirement, and health and retirement coverage. The index has recently been operationalized and validated in Germany. Given that the quantitative evidence for the framework is limited to Germany so far, we aimed to translate and validate an English version of the LLWI using a sample of older U.S. employees (N = 279). Findings regarding the psychometric properties of the measure are presented, supporting the domain level factor structure through confirmatory factor analyses, but revealing some redundancy among the items for the overall 9 domain factor structure. Multigroup factor analyses comparing the U.S. sample to a German sample (N = 349) further confirmed configural and (partial) metric measurement invariance of the English version of the LLWI. Results also supported convergent and discriminant validity as well as criterion and incremental validity regarding individual level attitudinal, health-related, intention, and behavioral outcomes. Based on these findings, implications for the use of the LLWI in research and practice and future research directions are discussed.