Recent work examines the initial experiences of the upwardly mobile at work (i.e., workers from lower-class backgrounds who enter upper-class contexts), aligning with an increasing focus on diversifying white-collar organizations. Yet, prior work has largely failed to consider how these changes in social class affect people’s beliefs about themselves over time. In cross-sectional and longitudinal data (N = 4,335), we explore whether the upwardly mobile’s subjective class identification and sense of fit with their new social class change over time to match those from higher-class backgrounds. We find that upwardly mobile alumni of elite-educational institutions tend to experience similar employment and income outcomes as their upper-class peers, yet experience often life-long gaps in identification and fit. In a Pilot, we find evidence that the upwardly mobile maintain their lower-class identity and experience less identification and fit in their new upper-class context, even after many decades. We build on these findings using a longitudinal approach (Study 1) and a large, cross-sectional survey with alumni of an elite professional school (Study 2). Rather than seamlessly transitioning to their new upper-class contexts, these results suggest that the psychological effects of the upwardly mobile’s social class background are relatively sticky and linger over time.