Does a new partnership differ from its preceding one? This study investigates whether relationship dynamics change as people transition from 1 partnership to another and examines a number of predictors that might explain variation in change trajectories. We draw on data gathered from 554 focal participants in the German Family Panel (pairfam) study surveyed at 4 time points spanning 2 intimate unions to answer these questions. Latent change score modeling results showed eventual stability in 5 of 7 constructs under investigation. When looking at overall change from Time 1 in Partnership 1 to Time 2 of Partnership 2, there were no mean-level changes in relationship and sexual satisfaction, perceptions of relational instability, or frequency of conflictual and intimate exchanges. Sexual frequency and partner admiration improved across partnerships. Further analyses showed much change unfolded in the interim; all constructs showed significant deterioration as Partnership 1 drew to a close, marked improvements as individuals moved from the end of Partnership 1 into their next union, and worsening across the 1st year of Partnership 2. Neuroticism and relationship length were the most consistent predictors of change across partnerships: Those in shorter Partnership 1 relationships and with higher neuroticism typically experienced decreases in functioning across partnerships. These findings provide support for an eventual stability conceptualization of relationship development across partnerships. (PsycINFO Database Record (c) 2019 APA, all rights reserved).