Previous research has focused on general best practices for onboarding organizational newcomers. In this study, we shift the conversation to address the question: for whom are certain socialization tactics more or less beneficial? Whereas institutionalized socialization tactics provide considerable structure and help newcomers adjust, less is known about whether and how individual psychological differences cause some newcomers to react differently to the same tactics. To examine the interplay between organizational socialization efforts and newcomer individual differences, we hypothesize that newcomers’ work locus of control (WLOC) moderates the relationship between socialization tactics and voluntary turnover. We also examine the indirect role of newcomer work adjustment—role clarity, work mastery, social integration—and job embeddedness in transmitting the interaction between socialization tactics and WLOC to turnover. Data collected from 676 newcomers in various organizations provided general support for our hypotheses: Newcomers with an external WLOC showed higher social integration and embeddedness and lower turnover under institutionalized tactics, but lower social integration and embeddedness and higher turnover under individualized tactics. Their turnover was also reduced from individualized to institutionalized tactics. In contrast, newcomers with an internal WLOC were less influenced by either socialization tactic approach in terms of their social integration, embeddedness, or turnover.