In a 3-year longitudinal study on 989 emerging adults, we assessed self-efficacy in dealing with work-family conflicts and different indices of work and relationships characteristics (e.g., satisfaction, commitment, and stress). In addition, we assessed different indices of health functioning (e.g., sick days, body complaints, internalizing and externalizing symptoms, and well-being). Latent class growth analyses revealed three different trajectories of competence with work-to-partnership conflicts over time that were related to work, romantic relationships, and health. Emerging adults in the high stable group (characterized by high levels of selfefficacy in dealing with conflicts in work and partnerships) remained in considerably better health than those in the other two groups. Emerging adults following the moderate increasing and the low increasing trajectories (e.g., with increasing competencies, starting from moderate and low mean levels in self-efficacy in dealing with work-partnership conflicts), experienced a stable commitment with their partners but more partnership-work conflicts over time. Their job satisfaction also increased over time.Overall health improved in those following the low increasing trajectory but remained considerably lower than in the other two groups. Results are interpreted with respect to the challenges but also the costs of efforts involved in adapting to the difficult transitions in the domains of love and work.